Photosensitive compositions, preparation methods thereof, and quantum dot polymer composite prepared therefrom

ABSTRACT

A photosensitive composition including a quantum dot dispersion, a reactive compound having at least two thiol groups, a photopolymerizable monomer having a carbon-carbon double bond, and a photoinitiator, wherein the quantum dot dispersion includes a carboxylic acid group-containing polymer and a quantum dot dispersed in the carboxylic acid group containing polymer, and wherein the carboxylic acid group-containing polymer includes a copolymer of a monomer combination including a first monomer having a carboxylic acid group and a carbon-carbon double bond and a second monomer having a carbon-carbon double bond and a hydrophobic moiety and not having a carboxylic acid group.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Korean Patent Application No.10-2015-0118208 filed in the Korean Intellectual Property Office on Aug.21, 2015, and all the benefits accruing therefrom under 35 U.S.C. §119,the content of which is incorporated herein in its entirety byreference.

BACKGROUND

1. Field

A photosensitive composition, a method of preparation thereof, a quantumdot-polymer composite prepared therefrom, and an electronic deviceincluding the same are disclosed.

2. Description of the Related Art

By colloidal synthesis, the particle size of quantum dots (QD) may berelatively freely and uniformly controlled. The QDs having a size ofless than or equal to about 10 nanometers may exhibit a more significantquantum confinement effect as their size decreases and thereby theirbandgap increases. In this case, the energy density of the QDs may beenhanced.

The QDs are applicable for various display devices (e.g., LCD) in theform of a QD-polymer composite.

For the application of the QD-polymer composites in various devices,there remains a need to develop a technique for patterning the quantumdot-polymer composite.

SUMMARY

An embodiment is related to a photosensitive composition capable ofpreparing a pattern of a quantum dot-polymer composite or a patternablequantum dot-polymer composite.

Another embodiment is related to a production method of theaforementioned photosensitive composition.

Another embodiment is related to a quantum dot-polymer compositeprepared from the aforementioned photosensitive composition.

Yet another embodiment provides a color filter including the quantumdot-polymer composite.

Yet another embodiment provides a display device including the quantumdot-polymer composite.

In an embodiment, a photosensitive composition includes:

a quantum dot (e.g., a plurality of quantum dots);

a carboxylic acid group (—COOOH)-containing polymer;

a reactive compound having at least two thiol groups;

a photopolymerizable monomer having a carbon-carbon double bond; and

a photoinitiator,

wherein the carboxylic acid group (—COOOH)-containing polymer includes acopolymer of a monomer combination including a first monomer having acarboxylic acid group and a carbon-carbon double bond and a secondmonomer having a carbon-carbon double bond and a hydrophobic moiety andnot having a carboxylic acid group.

The plurality of quantum dots may be dispersed by the carboxylic acidgroup (—COOOH)-containing polymer in the composition. Therefore, thephotosensitive composition includes a quantum dot dispersion includingthe carboxylic acid group (—COOOH)-containing polymer and a quantum dotdispersed in the carboxylic acid group containing polymer.

The quantum dot may include an organic ligand bound to a surfacethereof.

The organic ligand may have a hydrophobic moiety.

In some embodiments, the organic ligand does not include aphotopolymerizable functional group.

The organic ligand may include RCOOH, RNH₂, R₂NH, R₃N, RSH, R₃PO, R₃P,ROH, RCOOR′, RPO(OH)₂, R₂POOH (wherein R and R′ are independently a C5to C24 aliphatic hydrocarbon group or a C5 to C20 aromatic hydrocarbongroup), a polymeric organic ligand, or a combination thereof.

The quantum dot may include a Group II-VI compound, a Group III-Vcompound, a Group IV-VI compound, a Group IV element or compound, aGroup I-III-VI compound, a Group I-II-IV-VI compound, or a combinationthereof.

The carboxylic acid group-containing polymer may have an acid value ofgreater than or equal to about 50 milligrams of KOH per gram and lessthan or equal to about 200 milligrams of KOH per gram.

The carboxylic acid group-containing polymer may have an acid valuebetween about 100 milligrams of KOH per gram and 200 milligrams of KOHper gram.

The copolymer may include a first repeating unit derived from the firstmonomer and a second repeating unit derived from the second monomer, and

the first repeating unit may include a repeating unit represented byChemical Formula 1-1, a repeating unit represented by Chemical Formula1-2, or a combination thereof:

wherein

R¹ is hydrogen, a C1 to C3 alkyl group, or —(CH₂)_(n1)—COOH (wherein n1is 0 to 2),

R² is hydrogen, a C1 to C3 alkyl group, or —COOH,

L is a single bond, a C1 to C15 aliphatic hydrocarbon group, a C6 to C30aromatic hydrocarbon group, a C6 to C30 alicyclic hydrocarbon group, ora C1 to C15 aliphatic hydrocarbon group substituted with a C6 to C30aromatic hydrocarbon group or a C6 to C30 alicyclic hydrocarbon group,and

* indicates a portion linked to an adjacent atom;

wherein

R¹ is hydrogen, a C1 to C3 alkyl group, or —(CH₂)_(n1)—COOH (wherein n1is 0 to 2),

R² is hydrogen or a C1 to C3 alkyl group,

L is a C1 to C15 alkylene group, a C1 to C15 alkylene group wherein atleast one methylene group is substituted with —C(═O)—, —O—, or —C(═O)O—,a C6 to C30 aromatic hydrocarbon group, a C6 to C30 alicyclichydrocarbon group, or a C1 to C15 aliphatic hydrocarbon groupsubstituted with a C6 to C30 aromatic hydrocarbon group or a C6 to C30alicyclic hydrocarbon group,

n is an integer of 1 to 3, and

* indicates a portion linked to an adjacent atom.

The second repeating unit may include a repeating unit represented byChemical Formula 2, a repeating unit represented by Chemical Formula 4,a repeating unit represented by Chemical Formula 5, a repeating unitrepresented by Chemical Formula A, or a combination thereof:

wherein

R¹ is hydrogen or a C1 to C3 alkyl group,

R² is a C1 to C15 aliphatic hydrocarbon group, a C6 to C30 aromatichydrocarbon group, a C6 to C30 alicyclic hydrocarbon group, or a C1 toC15 aliphatic hydrocarbon group substituted with a C6 to C30 aromatichydrocarbon group or a C6 to C30 alicyclic hydrocarbon group,

R³ is hydrogen or a C1 to C3 alkyl group, and

* indicates a portion linked to an adjacent atom;

wherein

R¹ is hydrogen or a C1 to C3 alkyl group,

L is a C1 to C15 alkylene group, a C1 to C15 alkylene group wherein atleast one methylene group is substituted with —C(═O)—, —O—, or —C(═O)O—,a C6 to C30 aromatic hydrocarbon group, a C6 to C30 alicyclichydrocarbon group, or a C1 to C15 aliphatic hydrocarbon groupsubstituted with a C6 to C30 aromatic hydrocarbon group or a C6 to C30alicyclic hydrocarbon group,

R² is a C1 to C15 aliphatic hydrocarbon group, a C6 to C30 aromatichydrocarbon group, a C6 to C30 alicyclic hydrocarbon group, or a C1 toC15 aliphatic hydrocarbon group substituted with a C6 to C30 aromatichydrocarbon group or a C6 to C30 alicyclic hydrocarbon group,

R³ is hydrogen or a C1 to C3 alkyl group,

n is an integer of 1 to 3, and

* indicates a portion linked to an adjacent atom;

wherein

each of R¹ and R² is independently hydrogen or a C1 to C3 alkyl group,

Ar is a substituted or unsubstituted C6 to C30 aromatic hydrocarbongroup or a substituted or unsubstituted C6 to C30 alicyclic hydrocarbongroup, and

* indicates a portion linked to an adjacent atom;

wherein

R¹ is hydrogen or a C1 to C3 alkyl group,

R² is a C1 to C15 aliphatic hydrocarbon group, a C6 to C30 aromatichydrocarbon group, a C6 to C30 alicyclic hydrocarbon group, or a C1 toC15 aliphatic hydrocarbon group substituted with a C6 to C30 aromatichydrocarbon group or a C6 to C30 alicyclic hydrocarbon group,

R³ is hydrogen or a C1 to C3 alkyl group, and

* indicates a portion linked to an adjacent atom.

The monomer combination may further include a third monomer having acarbon-carbon double bond and a hydrophilic moiety and not having acarboxylic acid group.

The copolymer may include a third repeating unit derived from the thirdmonomer and the third repeating unit may be represented by ChemicalFormula 3:

wherein

each of R¹ and R² is independently hydrogen or a C1 to C3 alkyl group,

L is a C1 to C15 alkylene group, a C1 to C15 alkylene group wherein atleast one methylene group is substituted with —C(═O)—, —O—, or —C(═O)O—,a C6 to C30 aromatic hydrocarbon group, a C6 to C30 alicyclichydrocarbon group, or a C1 to C15 aliphatic hydrocarbon groupsubstituted with a C6 to C30 aromatic hydrocarbon group or a C6 to C30alicyclic hydrocarbon group,

Z is a hydroxyl group (—OH), a mercapto group (—SH), or an amino group(—NHR, wherein R is hydrogen or a C1 to C5 alkyl group) and

* indicates a portion linked to an adjacent atom.

In the copolymer, an amount of the first repeating unit may be greaterthan or equal to about 5 mole percent and less than or equal to about 95mole percent.

The carboxylic acid group-containing polymer may be a copolymer of afirst monomer selected from (meth)acrylic acid and at least one secondor third monomer selected from arylalkyl(meth)acrylate, hydroxyalkyl(meth)acrylate, and styrene.

A weight average molecular weight of the carboxylic acidgroup-containing polymer may be greater than or equal to about 1,000grams per mole and less than or equal to about 100,000 grams per mole.

The reactive compound may be represented by Chemical Formula 6:

wherein,

R¹ is hydrogen, a substituted or unsubstituted C1 to C30 linear orbranched alkyl group, a substituted or unsubstituted C6 to C30 arylgroup, a substituted or unsubstituted C7 to C30 arylalkyl group, asubstituted or unsubstituted C3 to C30 heteroaryl group, a substitutedor unsubstituted C4 to C30 heteroarylalkyl group, a substituted orunsubstituted C3 to C30 cycloalkyl group, a substituted or unsubstitutedC3 to C30 heterocycloalkyl group, a C1 to C10 alkoxy group, a hydroxygroup, —NH₂, a substituted or unsubstituted C1 to C30 amine group(—NRR′, wherein R and R′ are independently hydrogen or a C1 to C30linear or branched alkyl group), an isocyanate group, a halogen, —ROR′(wherein R is a substituted or unsubstituted C1 to C20 alkylene groupand R′ is hydrogen or a C1 to C20 linear or branched alkyl group), anacyl halide (—RC(═O)X, wherein R is a substituted or unsubstituted C1 toC20 alkylene group and X is a halogen), —C(═O)OR′ (wherein R′ ishydrogen or a C1 to C20 linear or branched alkyl group), —CN,—C(═O)ONRR′ (wherein R and R′ are independently hydrogen or a C1 to C20linear or branched alkyl group) or a combination thereof,

L₁ is a carbon atom, a substituted or unsubstituted C1 to C30 alkylenegroup, a substituted or unsubstituted C6 to C30 cycloalkylene group, asubstituted or unsubstituted C6 to C30 arylene group, or a substitutedor unsubstituted C6 to C30 heteroarylene group, wherein at least onemethylene (—CH₂—) of the substituted or unsubstituted C1 to C30 alkylenegroup may be replaced by sulfonyl (—S(═O)₂—), carbonyl (—C(═O)—), ether(—O—), sulfide (—S—), sulfoxide (—S(═O)—), ester (—C(═O)O—), amide(—C(═O)NR—) (wherein R is hydrogen or a C1 to C10 alkyl group), or acombination thereof,

Y₁ is a single bond, a substituted or unsubstituted C1 to C30 alkylenegroup, a substituted or unsubstituted C2 to C30 alkenylene group, or aC1 to C30 alkylene group or a C2 to C30 alkenylene group wherein atleast one methylene (—CH₂—) is replaced by sulfonyl (—S(═O)₂—), carbonyl(—C(═O)—), ether (—O—), sulfide (—S—), sulfoxide (—S(═O)—), ester(—C(═O)O—), amide (—C(═O)NR—) (wherein R is hydrogen or a C1 to C10linear or branched alkyl group), imine (—NR—) (wherein R is hydrogen ora C1 to C10 linear or branched alkyl group), or a combination thereof,

m is an integer of 1 or more,

k1 is 0 or an integer of 1 or more, k2 is an integer of 1 or more, and

the sum of m and k2 is an integer of 3 or more,

provided that m does not exceed the valence of Y₁ when Y₁ is not asingle bond, and

provided that the sum of k1 and k2 does not exceed the valence of L₁.

The reactive compound may include a compound of Chemical Formula 6-1:

wherein

L₁′ is carbon, a substituted or unsubstituted C2 to C20 group derivedfrom an alkane, a substituted or unsubstituted C6 to C30 group derivedfrom an arene, a substituted or unsubstituted C3 to C30 group derivedfrom a heteroarene, a substituted or unsubstituted C3 to C30 groupderived from a cycloalkane, or a substituted or unsubstituted C3 to C30group derived from a heterocycloalkane,

each of Y_(a) to Y_(d) is independently a single bond, a substituted orunsubstituted C1 to C30 alkylene group, a substituted or unsubstitutedC2 to C30 alkenylene group, or a C1 to C30 alkylene group or a C2 to C30alkenylene group wherein at least one methylene (—CH₂—) is replaced bysulfonyl (—S(═O)₂—), carbonyl (—C(═O)—), ether (—O—), sulfide (—S—),sulfoxide (—S(═O)—), ester (—C(═O)O—), amide (—C(═O)NR—) (wherein R ishydrogen or a C1 to C10 linear or branched alkyl group), imine (—NR—)(wherein R is hydrogen or a C1 to C10 linear or branched alkyl group),or a combination thereof, and

each of R_(a) to R_(d) is R¹ of Chemical Formula 6 or SH, provided thatat least two of R_(a) to R_(d) are SH.

The reactive compound may be ethoxylated pentaerythritoltetra(3-mercaptopropionate), trimethylolpropanetri(3-mercaptopropionate), trimethylol propane-tri(2-mercaptoacetate),glycol di-3-mercaptopropionate, polypropylene glycoldi(3-mercaptopropionate), ethoxylated trimethylolpropanetri(3-mercaptopropionate), glycol dimercaptoacetate, ethoxylated glycoldimercaptoacetate, 1,4-bis(3-mercaptobutyryloxy)butane,trimethylolpropane tris(3-mercaptopropionate),tris[2-(3-mercaptopropionyloxy)ethyl]isocyanurate,1,3,5-tris(3-mercaptobutyloxyethyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione,pentaerythritol tetrakis(3-mercaptopropionate), pentaerythritoltetrakis(2-mercaptoacetate), 1,6-hexanedithiol, 1,3-propanedithiol,1,2-ethanedithiol, a polyethylene glycol dithiol including 1 to 10ethylene glycol repeating units, or a combination thereof.

The photopolymerizable monomer including a carbon-carbon double bond mayinclude a diacrylate compound, a triacrylate compound, a tetraacrylatecompound, a pentaacrylate compound, a hexaacrylate compound, or acombination thereof.

The photosensitive composition may be developable by an alkali aqueoussolution.

A polymer composite prepared from the photosensitive composition mayshow a blue light conversion rate that is greater than or equal to about30% (or greater than or equal to about 40%) of its initial value afterbeing heated at 180° C. for 30 minutes.

The photosensitive composition may further include a solvent and mayinclude:

about 1 weight percent to about 40 weight percent of the quantum dots;

about 0.5 weight percent to about 35 weight percent of the carboxylicacid group-containing binder;

about 0.5 weight percent to about 30 weight percent of thephotopolymerizable monomer;

about 0.1 weight percent to about 40 weight percent of the reactivecompound;

about 0.01 weight percent to about 10 weight percent of thephotoinitiator; and

a balance amount of the solvent based on the total weight of thecomposition.

The photosensitive composition may further include a light diffusingagent selected from a metal oxide particle, a metal particle, and acombination thereof.

The photosensitive composition may further include a dispersant for thelight diffusing agent.

The photosensitive composition may further include a dispersant for thequantum dots.

In another embodiment, a production method of the aforementionedphotosensitive composition includes:

dissolving a carboxylic acid group (—COOOH)-containing polymer in asolvent to prepare a solution;

combining a plurality of quantum dots (that may have an organic ligandbound to a surface thereof) with the solution to obtain a quantum dotdispersion; and

combining the quantum dot dispersion with at least one of a reactivecompound having at least two thiol groups, a photopolymerizable monomerhaving a carbon-carbon double bond, a photoinitiator, and a solvent.

In another embodiment, a quantum dot-polymer composite includes:

a matrix including a carboxylic acid group (—COOOH)-containing polymerand a polymerization product of a photopolymerizable monomer having acarbon-carbon double bond and a reactive compound having at least twothiol groups; and

a plurality of quantum dots that may include an organic ligand bound toa surface thereof;

wherein the COOOH-containing polymer includes a copolymer of a monomercombination including a first monomer having a carboxylic acid group anda carbon-carbon double bond and a second monomer having a carbon-carbondouble bond and a hydrophobic moiety and not having a carboxylic acidgroup; and

the plurality of quantum dots are dispersed (e.g., separated from oneanother) in the matrix (e.g., without agglomeration).

The copolymer may be a linear polymer. The photopolymerizable monomermay include a monomer having at least three (meth)acrylate groups andthe polymerization product may include a crosslinked polymer.

The organic ligand may include a hydrophobic moiety and it may includeRCOOH, RNH₂, R₂NH, R₃N, RSH, R₃PO, R₃P, ROH, RCOOR′, RPO(OH)₂, R₂POOH(wherein R and R′ are independently a C5 to C24 aliphatic hydrocarbongroup or a C5 to C20 aromatic hydrocarbon group), a polymeric organicligand, or a combination thereof.

The carboxylic acid group-containing polymer may have an acid value ofgreater than about 60 milligrams of KOH per gram and less than or equalto about 200 milligrams of KOH per gram.

In the photosensitive composition, the copolymer may include a firstrepeating unit derived from the first monomer and a second repeatingunit derived from the second monomer, and

the first repeating unit may include a repeating unit represented byChemical Formula 1-1, a repeating unit represented by Chemical Formula1-2, or a combination thereof:

wherein

R¹ is hydrogen, a C1 to C3 alkyl group, or —(CH₂)_(n1)—COOH (wherein n1is 0 to 2),

R² is hydrogen, a C1 to C3 alkyl group, or —COOH,

L is a single bond, a C1 to C15 aliphatic hydrocarbon group, a C6 to C30aromatic hydrocarbon group, a C6 to C30 alicyclic hydrocarbon group, ora C1 to C15 aliphatic hydrocarbon group substituted with a C6 to C30aromatic hydrocarbon group or a C6 to C30 alicyclic hydrocarbon group,and

* indicates a portion linked to an adjacent atom;

wherein

R¹ is hydrogen, a C1 to C3 alkyl group, or —(CH₂)_(n1)—COOH (wherein n1is 0 to 2),

R² is hydrogen or a C1 to C3 alkyl group,

L is a C1 to C15 alkylene group, a C1 to C15 alkylene group wherein atleast one methylene group is substituted with —C(═O)—, —O—, or —C(═O)O—,a C6 to C30 aromatic hydrocarbon group, a C6 to C30 alicyclichydrocarbon group, or a C1 to C15 aliphatic hydrocarbon groupsubstituted with a C6 to C30 aromatic hydrocarbon group or a C6 to C30alicyclic hydrocarbon group,

n is an integer of 1 to 3, and

* indicates a portion linked to an adjacent atom.

The second repeating unit may include a repeating unit represented byChemical Formula 2, a repeating unit represented by Chemical Formula 4,a repeating unit represented by Chemical Formula 5, a repeating unitrepresented by Chemical Formula A, or a combination thereof:

wherein

R¹ is hydrogen or a C1 to C3 alkyl group,

R² is a C1 to C15 aliphatic hydrocarbon group, a C6 to C30 aromatichydrocarbon group, a C6 to C30 alicyclic hydrocarbon group, or a C1 toC15 aliphatic hydrocarbon group substituted with a C6 to C30 aromatichydrocarbon group or a C6 to C30 alicyclic hydrocarbon group,

R³ is hydrogen or a C1 to C3 alkyl group, and

* indicates a portion linked to an adjacent atom;

wherein

R¹ is hydrogen or a C1 to C3 alkyl group,

L is a C1 to C15 alkylene group, a C1 to C15 alkylene group wherein atleast one methylene group is substituted with —C(═O)—, —O—, or —C(═O)O—,a C6 to C30 aromatic hydrocarbon group, a C6 to C30 alicyclichydrocarbon group, or a C1 to C15 aliphatic hydrocarbon groupsubstituted with a C6 to C30 aromatic hydrocarbon group or a C6 to C30alicyclic hydrocarbon group,

R² is a C1 to C15 aliphatic hydrocarbon group, a C6 to C30 aromatichydrocarbon group, a C6 to C30 alicyclic hydrocarbon group, or a C1 toC15 aliphatic hydrocarbon group substituted with a C6 to C30 aromatichydrocarbon group or a C6 to C30 alicyclic hydrocarbon group,

R³ is hydrogen or a C1 to C3 alkyl group,

n is an integer of 1 to 3, and

* indicates a portion linked to an adjacent atom;

wherein

each of R¹ and R² is independently hydrogen or a C1 to C3 alkyl group,

Ar is a substituted or unsubstituted C6 to C30 aromatic hydrocarbongroup or a substituted or unsubstituted C6 to C30 alicyclic hydrocarbongroup, and

* indicates a portion linked to an adjacent atom;

wherein

R¹ is hydrogen or a C1 to C3 alkyl group,

R² is a C1 to C15 aliphatic hydrocarbon group, a C6 to C30 aromatichydrocarbon group, a C6 to C30 alicyclic hydrocarbon group, or a C1 toC15 aliphatic hydrocarbon group substituted with a C6 to C30 aromatichydrocarbon group or a C6 to C30 alicyclic hydrocarbon group,

R³ is hydrogen or a C1 to C3 alkyl group, and

* indicates a portion linked to an adjacent atom.

The monomer combination may further include a third monomer having acarbon-carbon double bond and a hydrophilic moiety and not having acarboxylic acid group.

The copolymer may include a third repeating unit derived from the thirdmonomer, and the third repeating unit may be represented by ChemicalFormula 3:

wherein

each of R¹ and R² is independently hydrogen or a C1 to C3 alkyl group, Lis a C1 to C15 alkylene group, a C1 to C15 alkylene group wherein atleast one methylene group is substituted with —C(═O)—, —O—, or —C(═O)O—,a C6 to C30 aromatic hydrocarbon group, a C6 to C30 alicyclichydrocarbon group, or a C1 to C15 aliphatic hydrocarbon groupsubstituted with a C6 to C30 aromatic hydrocarbon group or a C6 to C30alicyclic hydrocarbon group,

Z is a hydroxyl group (—OH), a mercapto group (—SH), or an amino group(—NHR, wherein R is hydrogen or a C1 to C5 alkyl group), and

* indicates a portion linked to an adjacent atom.

In the carboxylic acid group-containing polymer, an amount of the firstrepeating unit may be greater than or equal to about 5 mole percent andless than or equal to about 95 mole percent.

The reactive compound may be represented by Chemical Formula 6:

wherein

R¹ is hydrogen, a substituted or unsubstituted C1 to C30 linear orbranched alkyl group, a substituted or unsubstituted C6 to C30 arylgroup, a substituted or unsubstituted C7 to C30 arylalkyl group, asubstituted or unsubstituted C3 to C30 heteroaryl group, a substitutedor unsubstituted C4 to C30 heteroarylalkyl group, a substituted orunsubstituted C3 to C30 cycloalkyl group, a substituted or unsubstitutedC3 to C30 heterocycloalkyl group, a C1 to C10 alkoxy group, a hydroxygroup, —NH₂, a substituted or unsubstituted C1 to C30 amine group(—NRR′, wherein R and R′ are independently hydrogen or a C1 to C30linear or branched alkyl group), an isocyanate group, a halogen, —ROR′(wherein R is a substituted or unsubstituted C1 to C20 alkylene group,and R′ is hydrogen or a C1 to C20 linear or branched alkyl group), anacyl halide (—RC(═O)X, wherein R is a substituted or unsubstituted C1 toC20 alkylene group and X is a halogen), —C(═O)OR′ (wherein R′ ishydrogen or a C1 to C20 linear or branched alkyl group), —CN,—C(═O)ONRR′ (wherein R and R′ are independently hydrogen or a C1 to C20linear or branched alkyl group) or a combination thereof,

L₁ is a carbon atom, a substituted or unsubstituted C1 to C30 alkylenegroup, a substituted or unsubstituted C6 to C30 cycloalkylene group, asubstituted or unsubstituted C6 to C30 arylene group, or a substitutedor unsubstituted C6 to C30 heteroarylene group, wherein at least onemethylene (—CH₂—) of the substituted or unsubstituted C1 to C30 alkylenegroup may be replaced by sulfonyl (—S(═O)₂—), carbonyl (—C(═O)—), ether(—O—), sulfide (—S—), sulfoxide (—S(═O)—), ester (—C(═O)O—), amide(—C(═O)NR—) (wherein R is hydrogen or a C1 to C10 alkyl group), or acombination thereof,

Y₁ is a single bond, a substituted or unsubstituted C1 to C30 alkylenegroup, a substituted or unsubstituted C2 to C30 alkenylene group, or aC1 to C30 alkylene group or a C2 to C30 alkenylene group wherein atleast one methylene (—CH₂—) is replaced by sulfonyl (—S(═O)₂—), carbonyl(—C(═O)—), ether (—O—), sulfide (—S—), sulfoxide (—S(═O)—), ester(—C(═O)O—), amide (—C(═O)NR—) (wherein R is hydrogen or a C1 to C10linear or branched alkyl group), imine (—NR—) (wherein R is hydrogen ora C1 to C10 linear or branched alkyl group), or a combination thereof,

m is an integer of 1 or more,

k1 is 0 or an integer of 1 or more, k2 is an integer of 1 or more, and

the sum of m and k2 is an integer of 3 or more,

provided that when Y₁ is not a single bond, m does not exceed thevalence of Y₁, and

provided that the sum of k1 and k2 does not exceed the valence of L₁.

The reactive compound may include a compound of Chemical Formula 6-1:

wherein,

L₁′ is carbon, a substituted or unsubstituted C2 to C20 group derivedfrom an alkane, a substituted or unsubstituted C6 to C30 group derivedfrom an arene, a substituted or unsubstituted C3 to C30 group derivedfrom a heteroarene, a substituted or unsubstituted C3 to C30 groupderived from a cycloalkane, or a substituted or unsubstituted C3 to C30group derived from a heterocycloalkane,

each of Y_(a) to Y_(d) is independently a single bond, a substituted orunsubstituted C1 to C30 alkylene group, a substituted or unsubstitutedC2 to C30 alkenylene group, or a C1 to C30 alkylene group or a C2 to C30alkenylene group wherein at least one methylene (—CH₂—) is replaced bysulfonyl (—S(═O)₂—), carbonyl (—C(═O)—), ether (—O—), sulfide (—S—),sulfoxide (—S(═O)—), ester (—C(═O)O—), amide (—C(═O)NR—) (wherein R ishydrogen or a C1 to C10 linear or branched alkyl group), imine (—NR—)(wherein R is hydrogen or a C1 to C10 linear or branched alkyl group),or a combination thereof, and

each of R_(a) to R_(d) are R¹ of Chemical Formula 6 or SH, provided thatat least two of R_(a) to R_(d) are SH.

The quantum dot-polymer composite may be a pattern.

Another embodiment provides a color filter including the aforementionedquantum dot-polymer composite.

Yet another embodiment provides a display device including the quantumdot-polymer composite.

The aforementioned photosensitive composition may prepare a quantumdot-polymer composite pattern in an environmentally friendly manner. Thephotosensitive composition of the embodiments may be applied to aconventional photo-resist process without any additional surfacetreatment for the quantum dots. The pattern thus prepared may showenhanced stability even under heat-treatment carried out during thephoto-resist process.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects will become apparent and more readilyappreciated from the following description of the embodiments, taken inconjunction with the accompanying drawings in which:

FIG. 1 is a view showing a pattern forming process according to anembodiment to explain critical dimension uniformity;

FIG. 2 is a photographic image showing a quantum dot-binder dispersionprepared in Example 1;

FIG. 3 is an optical microscope photograph of the quantum dot-polymercomposite pattern prepared in Example 1;

FIG. 4 is an electron-microscopic image showing quantum dots dispersedin the pattern prepared in Example 1;

FIG. 5 is a view showing graphs plotting blue light conversion rate(percent, %) versus heat treating times (i.e., a process maintenancerate) with respect to the quantum dot-polymer composite patternsprepared in Examples 1 to 4 and Comparative Example 3, respectively;

FIG. 6 is a photographic image showing a mixture of the quantum dotcomposition prepared in Comparative Example 2;

FIG. 7 is a photographic image showing a quantum dot-binder dispersionprepared in Comparative Example 3;

FIG. 8 is an optical microscope photograph of the quantum dot-polymercomposite pattern prepared in Comparative Example 3;

FIG. 9 is a view showing a graph plotting blue light conversion rate(percent, %) versus heat treating times (i.e., a process maintenancerate) in Example 5;

FIG. 10 is a view showing a graph plotting blue light conversion rate(percent, %) versus heat treating times (i.e., a process maintenancerate) in Example 6;

FIG. 11 is a view showing a cross-sectional image of the patternprepared in Example 1;

FIG. 12 is a view showing a graph of photoconversion rate (percent, %)with respect to that of the film after PrB versus heat treating times,illustrating the effects of the number of thiol groups on the quantumdot-polymer composite pattern;

FIG. 13 is a schematic illustration of a cross-section of a displaydevice according to a non-limiting embodiment; and

FIG. 14 is a schematic illustration of a cross-section of a displaydevice according to a non-limiting embodiment.

DETAILED DESCRIPTION

Advantages and characteristics of this disclosure, and a method forachieving the same, will become evident referring to the followingexemplary embodiments together with the drawings attached hereto. Theembodiments, may, however, be embodied in many different forms andshould not be construed as being limited to the embodiments set forthherein. Accordingly, the exemplary embodiments are merely describedbelow, by referring to the figures, to explain aspects of the presentinventive concept. Expressions such as “at least one of,” when precedinga list of elements, modify the entire list of elements and do not modifythe individual elements of the list. If not defined otherwise, all terms(including technical and scientific terms) in the specification may bedefined as commonly understood by one skilled in the art. The termsdefined in a generally-used dictionary should be interpreted as having ameaning that is consistent with their meaning in the context of therelevant art and the present disclosure, and may not be interpretedideally or overly broad unless clearly defined. In addition, unlessexplicitly described to the contrary, the word “comprise” and variationssuch as “comprises” or “comprising”, and the word “include” andvariations such as “includes” or “including”, when used in thisspecification, specify the presence of stated features, regions,integers, steps, operations, elements, and/or components, but do notpreclude the presence or addition of one or more other features,regions, integers, steps, operations, elements, components, and/orgroups thereof. Therefore, the above words will be understood to implythe inclusion of stated elements but not the exclusion of any otherelements.

It will be understood that, although the terms first, second, third etc.may be used herein to describe various elements, components, regions,layers, and/or sections, these elements, components, regions, layers,and/or sections should not be limited by these terms. These terms areonly used to distinguish one element, component, region, layer, orsection from another element, component, region, layer, or section.Thus, a first element, component, region, layer, or section discussedbelow could be termed a second element, component, region, layer, orsection without departing from the teachings of the present embodiments.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting. As used herein, thesingular forms “a,” “an,” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise.

Spatially relative terms, such as “beneath,” “below,” “lower,” “above,”“upper” and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “beneath” otherelements or features would then be oriented “above” the other elementsor features. Thus, the exemplary term “below” can encompass both anorientation of above and below. The device may be otherwise oriented(rotated 90 degrees or at other orientations) and the spatially relativedescriptors used herein interpreted accordingly.

“About” or “approximately” as used herein is inclusive of the statedvalue and means within an acceptable range of deviation for theparticular value as determined by one of ordinary skill in the art,considering the measurement in question and the error associated withmeasurement of the particular quantity (i.e., the limitations of themeasurement system). For example, “about” can mean within one or morestandard deviations, or within ±10%, 5% of the stated value.

Exemplary embodiments are described herein with reference to crosssection illustrations that are schematic illustrations of idealizedembodiments. As such, variations from the shapes of the illustrations asa result, for example, of manufacturing techniques and/or tolerances,are to be expected. Thus, embodiments described herein should not beconstrued as limited to the particular shapes of regions as illustratedherein but are to include deviations in shapes that result, for example,from manufacturing. For example, a region illustrated or described asflat may, typically, have rough and/or nonlinear features. Moreover,sharp angles that are illustrated may be rounded. Thus, the regionsillustrated in the figures are schematic in nature and their shapes arenot intended to illustrate the precise shape of a region and are notintended to limit the scope of the present claims.

Further, the singular includes the plural unless mentioned otherwise.

In the drawings, the thickness of layers, films, panels, regions, etc.,are exaggerated for clarity. Like reference numerals designate likeelements throughout the specification.

It will be understood that when an element such as a layer, film,region, or substrate is referred to as being “on” another element, itcan be directly on the other element or intervening elements may also bepresent. In contrast, when an element is referred to as being “directlyon” another element, there are no intervening elements present.

As used herein, the term “alkyl group” refers to a group derived from astraight or branched chain saturated aliphatic hydrocarbon having thespecified number of carbon atoms and having a valence of at least one.

As used herein, the term “alkoxy group” refers to “alkyl-O—”, whereinthe term “alkyl” has the same meaning as described above.

As used herein, the term “alkenyl group” may refer to a straight orbranched chain, monovalent hydrocarbon group having at least onecarbon-carbon double bond.

As used herein, the term “alkynyl group” refers to a straight orbranched chain, monovalent hydrocarbon group having at least onecarbon-carbon triple bond.

As used herein, the term “cycloalkyl group” refers to a monovalent grouphaving one or more saturated rings in which all ring members are carbon.

As used herein, the term “aryl”, which is used alone or in combination,refers to an aromatic hydrocarbon group containing at least one ring andhaving the specified number of carbon atoms. The term “aryl” may beconstrued as including a group with an aromatic ring fused to at leastone cycloalkyl ring.

As used herein, the term “heteroaryl group” refers to an aryl groupincluding carbon and 1 to 3 heteroatoms selected from the groupconsisting of N, O, S, and P as ring atoms.

As used herein, the term “arylalkyl group” refers to a substituted orunsubstituted aryl group covalently linked to an alkyl group that islinked to a compound.

As used herein, the term “heteroarylalkyl group” refers to a substitutedor unsubstituted heteroaryl group covalently linked to an alkyl groupthat is linked to a compound.

As used herein, when a definition is not otherwise provided, the term“substituted” refers to a compound or a group or a moiety wherein atleast one of hydrogen atoms thereof is substituted with a substituentselected from a C1 to C30 alkyl group, a C2 to C30 alkynyl group, a C6to C30 aryl group, a C7 to C30 alkylaryl group, a C1 to C30 alkoxygroup, a C1 to C30 heteroalkyl group, a C3 to C30 heteroalkylaryl group,a C3 to C30 cycloalkyl group, a C3 to C15 cycloalkenyl group, a C6 toC30 cycloalkynyl group, a C2 to C30 heterocycloalkyl group, a halogen(—F, —Cl, —Br, or —I), a hydroxy group (—OH), a nitro group (—NO₂), acyano group (—CN), an amino group (—NRR′, wherein R and R′ areindependently hydrogen or a C1 to C6 alkyl group), an azido group (—N₃),an amidino group (—C(═NH)NH₂), a hydrazino group (—NHNH₂), a hydrazonogroup (═N(NH₂), an aldehyde group (—C(═O)H), a carbamoyl group(—C(O)NH₂), a thiol group (—SH), an ester group (—C(═O)OR, wherein R isa C1 to C6 alkyl group or a C6 to C12 aryl group), a carboxylic acidgroup (—COOOH) or a salt thereof (—C(═O)OM, wherein M is an organic orinorganic cation), a sulfonic acid group (—SO₃H) or a salt thereof(—SO₃M, wherein M is an organic or inorganic cation), a phosphoric acidgroup (—PO₃H₂) or a salt thereof (˜PO₃MH or —PO₃M₂, wherein M is anorganic or inorganic cation), and a combination thereof.

When a group containing a specified number of carbon atoms issubstituted with any of the groups listed in the preceding paragraph,the number of carbon atoms in the resulting “substituted” group isdefined as the sum of the carbon atoms contained in the original(unsubstituted) group and the carbon atoms (if any) contained in thesubstituent. For example, when the term “substituted C1 to C20 alkyl”refers to a C1 to C20 alkyl group substituted with a C6 to C20 arylgroup, the total number of carbon atoms in the resulting arylsubstituted alkyl group is C7 to C40.

As used herein, the term “monovalent organic functional group” refers toa C1 to C30 alkyl group, a C2 to C30 alkynyl group, a C6 to C30 arylgroup, a C7 to C30 alkylaryl group, a C1 to C30 alkoxy group, a C1 toC30 heteroalkyl group, a C3 to C30 heteroalkylaryl group, a C3 to C30cycloalkyl group, a C3 to C15 cycloalkenyl group, a C6 to C30cycloalkynyl group, or a C2 to C30 heterocycloalkyl group.

As used herein, when a definition is not otherwise provided, the term“hetero” refers to inclusion of one to three heteroatoms selected fromN, O, S, Si, and P.

As used herein, the term “alkylene group” refers to a straight orbranched saturated aliphatic hydrocarbon group having a valence of atleast two, optionally substituted with one or more substituents. Theterm “arylene group” refers to a functional group having a valence of atleast two obtained by removal of at least two hydrogens in an aromaticring, optionally substituted with one or more substituents.

As used herein, the term “alkenylene group” refers to a straight orbranched aliphatic hydrocarbon group having a valence of at least two,having at least one carbon-carbon double bond, optionally substitutedwith one or more substituents where indicated, provided that the valenceof the alkenylene group is not exceeded.

As used herein, the term “cycloalkylene group” refers to a cyclichydrocarbon group having a valence of at least two, optionallysubstituted with one or more substituents where indicated, provided thatthe valence of the cycloalkylene group is not exceeded.

As used herein, the term “arylene group” refers to a functional grouphaving a valence of at least two obtained by removal of two hydrogens inan aromatic ring, optionally substituted with one or more substituentswhere indicated, provided that the valence of the arylene group is notexceeded.

As used herein, the term “heteroarylene group” refers to a functionalgroup having a valence of at least two obtained by removal of twohydrogens in an aromatic ring, containing one to three heteroatomsselected from the group consisting of N, O, S, Si, and P as ring-formingelements, optionally substituted with one or more substituents whereindicated, provided that the valence of the heteroarylene group is notexceeded.

As used herein, the term “aliphatic organic group” refers to a C1 to C30linear or branched alkyl group, C2 to C30 linear or branched alkenylgroup, and C2 to C30 linear or branched alkynyl group, the term“aromatic organic group” refers to a C6 to C30 aryl group or a C2 to C30heteroaryl group, and the term “alicyclic organic group” refers to a C3to C30 cycloalkyl group, a C3 to C30 cycloalkenyl group, and a C3 to C30cycloalkynyl group.

As used herein, the term “(meth)acrylate” refers to acrylate and/ormethacrylate.

As used herein, the term “hydrophobic moiety” refers to a moiety thatcauses a given compound including the same to show agglomeration in anaqueous solution and to have a tendency to repel water. For example, thehydrophobic moiety may include an aliphatic hydrocarbon group having acarbon number of greater than or equal to 2 (alkyl, alkenyl, alkynyl,etc.), an aromatic hydrocarbon group having a carbon number of greaterthan or equal to 6 (phenyl, naphthyl, arylalkyl group, etc.), or analicyclic hydrocarbon group having a carbon number of greater than orequal to 5 (cyclohexyl, norbornenyl, etc.). The hydrophobic moietysubstantially lacks an ability to make a hydrogen bond with an ambientmedium and is not substantially mixed with the medium as its polaritydoes not match that of the medium.

As used herein, the term “group” refers to a group of Periodic Table.

As used herein, “Group II” refers to Group IIA and Group IIB, andexamples of Group II metal may be Cd, Zn, Hg, and Mg, but are notlimited thereto.

As used herein, “Group III” refers to Group IIIA and Group IIIB, andexamples of Group III metal may be Al, In, Ga, and Tl, but are notlimited thereto.

As used herein, “Group IV” refers to Group IVA and Group IVB, andexamples of a Group IV metal may be Si, Ge, and Sn, but are not limitedthereto. As used herein, the term “metal” may include a semi-metal suchas Si.

As used herein, “Group I” refers to Group IA and Group IB, and examplesmay include Li, Na, K, Ru, and Cs, but are not limited thereto.

As used herein, “Group V” refers to Group VA, and examples may includeN, P, As, Sb, and Bi, but are not limited thereto.

As used herein, “Group VI” refers to Group VIA, and examples may includeS, Se, and Te, but are not limited thereto.

As used herein, the term “visible light” refers to light having awavelength of about 390 nanometers (nm) to about 700 nm. As used herein,the term “UV light” refers to light having a wavelength of greater thanor equal to about 200 nm and less than about 390 nm.

As used herein, the term “blue light conversion rate” refers to a ratioof emitted light with respect to incident light. In some embodiments,the blue light conversion rate may be a ratio of emitted light amount ofthe quantum dot polymer composite to the absorbed light amount thereoffrom the excitation light (e.g., blue light), A total amount of theexcitation light (e.g., a total amount of the blue light, B) may beobtained by integrating a photoluminescent spectrum of the excitationlight. A PL spectrum of the quantum dot polymer composite is obtainedand from the PL spectrum thus obtained, an amount of the blue light (B′)and an amount of the light (A) that is emitted from the quantum dotpolymer composite and has a green and/or red wavelength range aremeasured, respectively. Then, the light conversion rate is calculated bythe following equation:

A/(B−B′)×100=light conversion rate (%).

As used herein, the term “dispersion” refers to a dispersion wherein adispersed phase is a solid and a continuous phase includes a liquid. Forexample, the term “dispersion” may refer to a colloidal dispersionwherein the dissolved or dispersed phase has a dimension of about 1 nmto about 1 micrometer (μm).

Hereinafter, the term “binder” or “carboxylic acid group-containingbinder” refers to the “carboxylic acid group-containing polymer.”

In an embodiment, a photosensitive composition includes:

a plurality of quantum dots (that may have an organic ligand on asurface thereof);

a carboxylic acid group (—COOOH)-containing polymer

a reactive compound having at least two thiol groups;

a photopolymerizable monomer having a carbon-carbon double bond; and

a photoinitiator.

The carboxylic acid group (—COOOH)-containing polymer includes acopolymer of a monomer combination including a first monomer having acarboxylic acid group and a carbon-carbon double bond and a secondmonomer having a carbon-carbon double bond and a hydrophobic moiety andnot having a carboxylic acid group.

The plurality of quantum dots may be dispersed (for example, separatedfrom one another) by the carboxylic acid group (—COOOH)-containingpolymer to form a quantum dot dispersion. The quantum dot dispersionincludes the carboxylic acid group (—COOOH)-containing polymer and theplurality of quantum dots dispersed in the carboxylic acid group(—COOOH)-containing polymer. The quantum dot dispersion may furtherinclude a solvent.

The quantum dot (hereinafter also referred to as a semiconductornanocrystal) is not particularly limited, and may be prepared in anyknown method or is a commercially available. For example, the quantumdot may be a Group II-VI compound, a Group III-V compound, a Group IV-VIcompound, a Group IV element or compound, a Group I-III-VI compound, aGroup I-II-IV-VI compound, or a combination thereof.

The Group II-VI compound may be selected from:

a binary element compound selected from CdSe, CdTe, ZnS, ZnSe, ZnTe,ZnO, HgS, HgSe, HgTe, MgSe, MgS, and a combination thereof;

a ternary element compound selected from CdSeS, CdSeTe, CdSTe, ZnSeS,ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS,CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS, and a combinationthereof; and

a quaternary element compound selected from HgZnTeS, CdZnSeS, CdZnSeTe,CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe, and acombination thereof.

The Group II-VI compound may further include a Group III metal.

The Group III-V compound may be selected from:

a binary element compound selected from GaN, GaP, GaAs, GaSb, AlN, AlP,AlAs, AlSb, InN, InP, InAs, InSb, and a combination thereof;

a ternary element compound selected from GaNP, GaNAs, GaNSb, GaPAs,GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs,InPSb, InZnP, and a combination thereof; and

a quaternary element compound selected from GaAlNP, GaAlNAs, GaAlNSb,GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP,InAlNAs, InAlNSb, InAlPAs, InAlPSb, and a combination thereof.

The Group III-V compound may further include a Group II metal (e.g.,InZnP).

The Group IV-VI compound may be selected from:

a binary element compound selected from SnS, SnSe, SnTe, PbS, PbSe,PbTe, and a combination thereof;

a ternary element compound selected from SnSeS, SnSeTe, SnSTe, PbSeS,PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, and a combination thereof; and

a quaternary element compound selected from SnPbSSe, SnPbSeTe, SnPbSTe,and a combination thereof.

Examples of the Group I-III-VI compound may include CuInSe₂, CuInS₂,CuInGaSe, and CuInGaS, but are not limited thereto.

Examples of the Group I-II-IV-VI compound may include CuZnSnSe andCuZnSnS, but are not limited thereto.

The Group IV element or compound may include:

a single-element selected from Si, Ge, and a combination thereof; and

a binary element compound selected from SiC, SiGe, and a combinationthereof.

The binary element compound, the ternary element compound or thequaternary element compound may be respectively included in a uniformconcentration in the particle or partially different concentrations inthe same particle. The semiconductor nanocrystal particle may have acore-shell structure wherein a first semiconductor nanocrystal issurrounded by a second semiconductor nanocrystal that is different fromthe first semiconductor nanocrystal. The interface between the core andthe shell may have a concentration gradient wherein the concentration ofan element of the shell decreases toward the core. In addition, thesemiconductor nanocrystal particle may have a semiconductor nanocrystalcore and a multi-layered shell surrounding the semiconductor nanocrystalcore. The core and multi-layered shell structure has at least two layersof the shell wherein each layer may be a single composition, an alloy,or the one having a concentration gradient.

In the semiconductor nanocrystal particle, the materials of the shellmay have a larger energy bandgap than that of the core, and thereby thesemiconductor nanocrystal may exhibit a quantum confinement effect moreeffectively. In case of a multi-layered shell type of semiconductornanocrystal particle, the bandgap of the material of an outer layer ofthe shell may be higher energy than that of the material of an innerlayer of the shell (a layer that is closer to the core). In this case,the semiconductor nanocrystal particle may emit light of a UV toinfrared wavelength range.

The semiconductor nanocrystal may have a quantum yield of greater thanor equal to about 10%, or greater than or equal to about 30%, forexample, greater than or equal to about 50%, greater than or equal toabout 60%, greater than or equal to about 70%, or greater than or equalto about 90%.

For use in display devices, the semiconductor nanocrystal may have anarrower FWHM so as to realize enhanced color purity or colorreproducibility. The semiconductor nanocrystal may have a FWHM of lessthan or equal to about 45 nm, for example less than or equal to about 40nm, or less than or equal to about 30 nm. While not wishing to be boundby theory, it is understood that within such ranges, a device includingthe nanocrystal may have enhanced color purity or improved colorreproducibility.

The quantum dot (i.e., the semiconductor nanocrystal particle) may havea particle diameter (the longest diameter for a non-spherically shapedparticle) of about 1 nm to about 100 nm. For example, the quantum dotmay have a particle diameter (the longest diameter for a non-sphericallyshaped particle) of about 1 nm to about 20 nm, for example, from 2 nm(or from 3 nm) to 15 nm.

The quantum dot may have a generally-used shape in this art, and is notparticularly limited. For example, the quantum dot may includespherical, pyramidal, multi-armed, or cubic nanoparticles, nanotubes,nanowires, nanofibers, nanoplate particles, a combination thereof, orthe like.

The quantum dot is commercially available or may be synthesized in anymethod. For example, several nano-sized quantum dots may be synthesizedaccording to a wet chemical process. In the wet chemical process,precursors react in an organic solvent to grow nanocrystal particles,and the organic solvent or a ligand compound may coordinate (or bound)to the surface of the semiconductor nanocrystal, thereby controlling thegrowth of the nanocrystal. Examples of the organic solvent and ligandcompound are known. The organic solvent coordinated to the surface ofthe quantum dot may affect stability of a device, and thus excessorganic materials that are not coordinated to the surface of the quantumdot may be removed by pouring the quantum dot into an excessive amountof a non-solvent, and centrifuging the resulting mixture. Examples ofthe non-solvent may be acetone, ethanol, methanol, and the like, but arenot limited thereto. After the removal of extra organic materials, theamount of the organic materials coordinated to the surface of thequantum dots may be less than or equal to about 50% by weight, forexample, less than or equal to about 30 wt %, less than or equal toabout 20 wt %, or less than or equal to about 10 wt % based on the totalweight of the quantum dots. The organic material may include a ligandcompound, an organic solvent, or a combination thereof.

The quantum dot may have an organic ligand having a hydrophobic moietybonded to the surface of the quantum dot. In an embodiment, the organicligand having a hydrophobic moiety may include RCOOH, RNH₂, R₂NH, R₃N,RSH, R₃PO, R₃P, ROH, RCOOR′, RPO(OH)₂, R₂POOH (wherein R and R′ areindependently a C5 to C24 alkyl group, a C5 to C24 alkenyl group, or aC5 to C20 aryl group), a polymeric organic ligand, or a combinationthereof.

Examples of the organic ligand compound bonded to the surface of thequantum dot may include:

thiol compounds such as methane thiol, ethane thiol, propane thiol,butane thiol, pentane thiol, hexane thiol, octane thiol, dodecane thiol,hexadecane thiol, octadecane thiol, or benzyl thiol;

amine compounds such as methylamine, ethylamine, propylamine,butylamine, pentylamine, hexylamine, octylamine, nonylamine, decylamine,dodecylamine, hexadecylamine, octadecylamine, dimethylamine,diethylamine, dipropylamine, tributylamine, or trioctylamine;

carboxylic acid compounds such as methanoic acid, ethanoic acid,propanoic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoicacid, octanoic acid, dodecanoic acid, hexadecanoic acid, octadecanoicacid, oleic acid, or benzoic acid;

phosphine compounds such as methyl phosphine, ethyl phosphine, propylphosphine, butyl phosphine, pentyl phosphine, octyl phosphine, dioctylphosphine, tributyl phosphine, or trioctyl phosphine;

phosphine oxide compounds such as methyl phosphine oxide, ethylphosphine oxide, propyl phosphine oxide, butyl phosphine oxide, pentylphosphine oxide, tributyl phosphine oxide, octylphosphine oxide, dioctylphosphine oxide, or trioctyl phosphine oxide;

diphenyl phosphine, triphenyl phosphine, or oxide compounds thereof;

a C5 to C20 alkylphosphinic acid such as hexylphosphinic acid,octylphosphinic acid, dodecanephosphinic acid, tetradecanephosphinicacid, hexadecanephosphinic acid, or octadecane phosphinic acid;

and the like, but are not limited thereto.

The quantum dot may include the hydrophobic organic ligand alone or as amixture of two or more.

An amount of the quantum dot including the organic ligand may be greaterthan or equal to about 1 percent by weight (wt %), for example, greaterthan or equal to about 5 wt %, or greater than or equal to about 10 wt%, based on the total amount of the composition. The amount of thequantum dot including the organic ligand may be less than or equal toabout 40 wt %, for example, less than or equal to about 35 wt %, basedon the total amount of the composition. In some embodiments, the amountof the quantum dot including the organic ligand may be about 5 wt % to40 wt %, based on a total weight of solid contents (non-volatilecomponents) of the compositions.

Using a photoluminescent type of color filter instead of the absorptiontype of color filter may widen the viewing angle and improve theluminance. The quantum dot may have a theoretical quantum yield (QY) ofabout 100%, and may emit light having high color purity (e.g., a fullwidth at half maximum (FWHM) of less than or equal to about 40 nm), andthus it may achieve the enhanced luminous efficiency and the improvedcolor reproducibility. Accordingly, it is believed that using a colorfilter including a quantum dot polymer composite may allow realizing adisplay having high brightness, a wide viewing angle, and high colorreproducibility. In order to realize the aforementioned properties,however, it may be required to well-disperse a relatively large numberof quantum dots (e.g., at least 5 wt % of the quantum dots based on thetotal amount of the composite) in the polymer composite.

Meanwhile, as a method of forming a pattern including quantum dots inconventional arts, U.S. Pat. No. 7,199,393 discloses that quantum dotshaving a photosensitive functional group on the surface thereof are usedin a patterning method, the entire content of which is incorporatedherein by reference. In the disclosed method, a photosensitivefunctional group is introduced onto the surface of a quantum dot andsubjected to photopolymerization, if desired, together with aphotopolymerizable monomer, to prepare a quantum dot-polymer compositepattern. But the disclosed method requires an additional process of asurface treatment of quantum dots and needs to use an organic solvent toform a pattern during a developing process.

On the other hand, when the quantum dots (e.g., in which organic ligandis bound to the surface) are mixed with the alkali-developablephotoresist without performing any surface treatment in an attempt toprovide an alkali-developable quantum dot-polymer composite pattern,they are not dispersed well or are even agglomerated because the quantumdots have poor compatibility with the conventional photoresist. In orderfor the patterned quantum dot-polymer composite to be applied in a colorfilter, a large amount of quantum dots should be able to be included inthe composite. When the quantum dots cannot be dispersed in thecomposition, it becomes impossible to provide a uniform pattern.

In the photosensitive composition according to an embodiment, thequantum dot including an organic ligand (e.g., having a hydrophobicmoiety) on the surface is first dispersed in the solution of thecarboxylic acid group-containing binder having a hydrophobic moiety. Theobtained quantum dot-binder dispersion is then mixed with the othercomponents for a photoresist. As a results, the quantum dots may be welldispersed in the alkali-developable photoresist. Therefore, in case ofthe photosensitive composition according to an embodiment, a relativelylarge amount of the quantum dots may be well dispersed in thephotoresist composition. Without wishing to be bound by any theory, itis understood that when the quantum dots are dispersed in the solutionof the carboxylic acid group-containing binder having a hydrophobicmoiety, the binder may facilitate the formation of the dispersionincluding the quantum dots, and the quantum dots dispersed with the helpof the binder may maintain their dispersed state even when theyconstitute a photoresist composition.

Therefore, the photosensitive composition of the embodiments includes aquantum dot dispersion that includes a carboxylic acid group-containingbinder and a plurality of the quantum dots dispersed (e.g., separatedfrom one another) in the binder. The carboxylic acid group-containingbinder may include a copolymer of a monomer combination including thefirst monomer having a carboxylic acid group and a carbon-carbon doublebond and the second monomer having a carbon-carbon double bond and ahydrophobic moiety but including no carboxylic acid group.

As the photosensitive composition according to an embodiment may providea quantum dot-polymer composite pattern including the quantum dot withno photo-polymerizable functional group (e.g., carbon-carbon double bondsuch as (meth)acrylate), no surface treatment for the quantum dotsurface is necessary. In addition, a developing process for a patternprepared from the aforementioned photosensitive composition does notrequire a use of an organic solvent such as toluene or NMP in thedeveloping process.

Examples of the first monomer may include, but are not limited to,acrylic acid, methacrylic acid, maleic acid, itaconic acid, fumaricacid, 3-butenoic acid, carboxylic acid vinyl ester compounds such asvinyl acetate, and vinyl benzoate. The first monomer may include one ormore compounds.

Examples of the second monomer may include, but are not limited to:

alkenyl aromatic compounds such as styrene, α-methyl styrene, vinyltoluene, or vinyl benzyl methyl ether;

unsaturated carboxylic acid ester compounds such as methyl acrylate,methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate,butyl methacrylate, benzyl acrylate, benzyl methacrylate, cyclohexylacrylate, cyclohexyl methacrylate, phenyl acrylate, or phenylmethacrylate;

unsaturated carboxylic acid amino alkyl ester compounds such as 2-aminoethyl acrylate, 2-amino ethyl methacrylate, 2-dimethyl amino ethylacrylate, or 2-dimethyl amino ethyl methacrylate;

maleimides such as N-phenylmaleimide, N-benzylmaleimide,N-alkylmaleimide;

unsaturated carboxylic acid glycidyl ester compounds such as glycidylacrylate or glycidyl methacrylate;

vinyl cyanide compounds such as acrylonitrile or methacrylonitrile; and

unsaturated amide compounds such as acrylamide or methacrylamide, butare not limited thereto.

As the second monomer, at least one compound may be used.

The carboxylic acid group-containing binder may have an acid value ofgreater than or equal to about 50 milligrams of KOH per gram (mg KOH/g)in order to disperse quantum dots, but the acid value may vary dependingon a chemical structure thereof (e.g., a chemical structure of a mainchain or a hydrophobic moiety at the side chain). For example, thecarboxylic acid group-containing binder may have an acid value ofgreater than or equal to about 60 mg KOH/g, greater than or equal toabout 70 mg KOH/g, greater than or equal to about 80 mg KOH/g, greaterthan or equal to about 90 mg KOH/g, greater than or equal to about 100mg KOH/g, greater than or equal to about 110 mg KOH/g, greater than orequal to about 120 mg KOH/g, greater than or equal to about 125 mgKOH/g, or greater than or equal to about 130 mg KOH/g. The carboxylicacid group-containing binder may have an acid value of, for example,less than or equal to about 200 mg KOH/g, for example, less than orequal to about 190 mg KOH/g, less than or equal to about 180 mg KOH/g,or less than or equal to about 160 mg KOH/g, but it is not limitedthereto. While not wishing to be bound by theory, it is understood thatwhen the quantum dots are mixed with a solution of a binder having theacid value within the aforementioned range to provide a quantumdot-binder dispersion, the obtained quantum dot-binder dispersion mayhave the improved compatibility with the other components for thephotoresist (e.g., photopolymerizable monomer, photoinitiator, solvent,etc.), and thereby the quantum dots may be well dispersed in the finalcomposition (i.e., photoresist composition) to form a pattern. In anembodiment, the carboxylic acid group-containing binder may have an acidvalue of about 100 mg KOH/g to about 200 mg KOH/g.

The carboxylic acid group-containing binder may include a copolymer of amonomer combination that includes the first and second monomers, and mayfurther include a third monomer having a carbon-carbon double bond and ahydrophilic moiety and not having a carboxylic acid group.

Examples of the third monomer may include 2-hydroxy ethyl acrylate,2-hydroxy ethyl methacrylate, 2-hydroxy butyl acrylate, and 2-hydroxybutyl methacrylate, but are not limited thereto. The third monomer mayinclude one or more compounds.

The first repeating unit may include a repeating unit represented byChemical Formula 1-1, a repeating unit represented by Chemical Formula1-2, or a combination thereof:

wherein

R¹ is hydrogen, a C1 to C3 alkyl group, or —(CH₂)_(n1)—COOH (wherein n1is 0 to 2),

R² is hydrogen, a C1 to C3 alkyl group, or —COOH,

L is a single bond, a C1 to C15 aliphatic hydrocarbon group such as a C1to C3 alkylene group, a C6 to C30 aromatic hydrocarbon group such as aC6 to C12 arylene group, a C6 to C30 alicyclic hydrocarbon group (acycloalkylene group or a cycloalkenylene group such as a norbornenemoiety, or a C1 to C15 aliphatic hydrocarbon group substituted with a C6to C30 aromatic hydrocarbon group or a C6 to C30 alicyclic hydrocarbongroup, and

* indicates a portion linked to an adjacent atom;

wherein

R¹ is hydrogen, a C1 to C3 alkyl group, or —(CH₂)_(n1)—COOH (wherein n1is 0 to 2),

R² is hydrogen or a C1 to C3 alkyl group,

L is a C1 to C15 alkylene group, a C1 to C15 alkylene group wherein atleast one methylene group is substituted with —C(═O)—, —O—, or —C(═O)O—,a C6 to C30 aromatic hydrocarbon group such as a C6 to C30 arylenegroup, a C6 to C30 alicyclic hydrocarbon group (e.g., a cycloalkylenegroup or a cycloalkenylene group such as a norbornene moiety), or a C1to C15 aliphatic hydrocarbon group substituted with a C6 to C30 aromatichydrocarbon group or a C6 to C30 alicyclic hydrocarbon group,

n is an integer of 1 to 3, and

* indicates a portion linked to an adjacent atom.

The second repeating unit may include a repeating unit represented byChemical Formula 2, a repeating unit represented by Chemical Formula 4,a repeating unit represented by Chemical Formula 5, a repeating unitrepresented by Chemical Formula A, or a combination thereof:

wherein

R¹ is hydrogen or a C1 to C3 alkyl group,

R² is a C1 to C15 aliphatic hydrocarbon group (e.g., a C1 to C15 alkylgroup such as methyl, ethyl, propyl, and the like), a C6 to C30 aromatichydrocarbon group (a C6 to C24 aryl group such as a phenyl group, anaphthyl group or the like), a C6 to C30 alicyclic hydrocarbon groupsuch as a cycloalkyl group (e.g., a cyclohexyl group, a norbornyl group,or the like), or a C1 to C15 aliphatic hydrocarbon group substitutedwith a C6 to C30 aromatic hydrocarbon group or a C6 to C30 alicyclichydrocarbon group (e.g., an arylalkyl group),

R³ is hydrogen or a C1 to C3 alkyl group, and

* indicates a portion linked to an adjacent atom;

wherein

R¹ is hydrogen or a C1 to C3 alkyl group,

L is a C1 to C15 alkylene group, a C1 to C15 alkylene group wherein atleast one methylene group is substituted with —C(═O)—, —O—, or —C(═O)O—,a C6 to C30 aromatic hydrocarbon group such as a C6 to C30 arylenegroup, a C6 to C30 alicyclic hydrocarbon group (e.g., a cycloalkylenegroup or a cycloalkenylene group such as a norbornene moiety), or a C1to C15 aliphatic hydrocarbon group substituted with a C6 to C30 aromatichydrocarbon group or a C6 to C30 alicyclic hydrocarbon group,

R² is a C1 to C15 aliphatic hydrocarbon group (e.g., a C1 to C15 alkylgroup such as methyl, ethyl, propyl, and the like), a C6 to C30 aromatichydrocarbon group (e.g., a C6 to C24 aryl group such as a phenyl group,a naphthyl group, or the like), a C6 to C30 alicyclic hydrocarbon groupsuch as a cycloalkyl group (e.g., a cyclohexyl group), a norbornylgroup, or the like, or a C1 to C15 aliphatic hydrocarbon groupsubstituted with a C6 to C30 aromatic hydrocarbon group or a C6 to C30alicyclic hydrocarbon group (e.g., an arylalkyl group),

R³ is hydrogen or a C1 to C3 alkyl group,

n is an integer of 1 to 3, and

* indicates a portion linked to an adjacent atom;

wherein

each of R¹ and R² is independently hydrogen or a C1 to C3 alkyl group,

Ar is a substituted or unsubstituted C6 to C30 aromatic hydrocarbongroup (e.g., an aryl group such as phenyl and an arylalkyl group such asbenzyl and the like), or a substituted or unsubstituted C6 to C30alicyclic hydrocarbon group, and

* indicates a portion linked to an adjacent atom;

wherein

R¹ is hydrogen or a C1 to C3 alkyl group,

R² is a C1 to C15 aliphatic hydrocarbon group, a C6 to C30 aromatichydrocarbon group, a C6 to C30 alicyclic hydrocarbon group (for example,a cycloalkyl group or a cycloalkenyl group such as norbornene), or a C1to C15 aliphatic hydrocarbon group substituted with a C6 to C30 aromatichydrocarbon group or a C6 to C30 alicyclic hydrocarbon group,

R³ is hydrogen or a C1 to C3 alkyl group, and

* indicates a portion linked to an adjacent atom.

The copolymer may further include a third repeating unit derived from athird monomer, and the third repeating unit may be represented byChemical Formula 3:

wherein

each of R¹ and R² is independently hydrogen or a C1 to C3 alkyl group,

L is a C1 to C15 alkylene group, a C1 to C15 alkylene group wherein atleast one methylene group is substituted with —C(═O)—, —O—, or —C(═O)O—,a C6 to C30 aromatic hydrocarbon group such as a C6 to C30 arylenegroup, a C6 to C30 alicyclic hydrocarbon group (e.g., a cycloalkylenegroup or a cycloalkenylene group such as a norbornene moiety), or a C1to C15 aliphatic hydrocarbon group substituted with a C6 to C30 aromatichydrocarbon group or a C6 to C30 alicyclic hydrocarbon group,

Z is a hydroxyl group (—OH), a mercapto group (—SH), or an amino group(—NHR, wherein R is hydrogen or a C1 to C5 alkyl group), and

* indicates a portion linked to an adjacent atom.

In an embodiment, the carboxylic acid group-containing binder may be acopolymer of (meth)acrylic acid (i.e., the first monomer) and at leastone second or third monomer selected from arylalkyl(meth)acrylate,hydroxyalkyl (meth)acrylate, and styrene.

In the carboxylic acid group-containing binder, an amount of the firstrepeating unit derived from the first monomer may be greater than orequal to about 10 mole percent (mol %), for example, greater than orequal to about 15 mol %, greater than or equal to about 25 mol %, orgreater than or equal to about 35 mol %. In the carboxylic acidgroup-containing binder, an amount of the first repeating unit may beless than or equal to about 90 mol %, for example, less than or equal toabout 89 mol %, less than or equal to about 88 mol %, less than or equalto about 87 mol %, less than or equal to about 86 mol %, less than orequal to about 85 mol %, less than or equal to about 80 mol %, less thanor equal to about 70 mol %, less than or equal to about 65 mol %, lessthan or equal to about 45 mol %, less than or equal to about 35 mol %,or less than or equal to about 25 mol %.

In the carboxylic acid group-containing binder, an amount of the secondrepeating unit derived from the second monomer may be greater than orequal to about 10 mol %, for example, greater than or equal to about 15mol %, greater than or equal to about 25 mol %, or greater than or equalto about 35 mol %. In the carboxylic acid group-containing binder, anamount of the second repeating unit may be less than or equal to about90 mol %, for example, less than or equal to about 89 mol %, less thanor equal to about 88 mol %, less than or equal to about 87 mol %, lessthan or equal to about 86 mol %, less than or equal to about 85 mol %,less than or equal to about 80 mol %, less than or equal to about 70 mol%, less than or equal to about 65 mol %, less than or equal to about 40mol %, less than or equal to about 35 mol %, or less than or equal toabout 25 mol %.

In the carboxylic acid group-containing binder, an amount of the thirdrepeating unit derived from the third monomer may be greater than orequal to about 1 mol %, for example, greater than or equal to about 5mol %, greater than or equal to about 10 mol %, or greater than or equalto about 15 mol %. In the carboxylic acid group-containing binder, anamount of the third repeating unit may be less than or equal to about 30mol %, for example, less than or equal to about 25 mol %, less than orequal to about 20 mol %, less than or equal to about 18 mol %, less thanor equal to about 15 mol %, or less than or equal to about 10 mol %.

The carboxylic acid group-containing binder may include a copolymer of a(meth)acrylic acid, and at least one monomer selected from anarylalkyl(meth)acrylate, a hydroxyalkyl (meth)acrylate, and styrene. Forexample, the carboxylic acid group-containing binder may include amethacrylic acid/methyl methacrylate copolymer, a methacrylicacid/benzyl methacrylate copolymer, a methacrylic acid/benzylmethacrylate/styrene copolymer, a methacrylic acid/benzylmethacrylate/2-hydroxy ethyl methacrylate copolymer, or a methacrylicacid/benzyl methacrylate/styrene/2-hydroxy ethyl methacrylate copolymer.

In another embodiment, the carboxylic acid group-containing binder mayinclude a multiple aromatic ring-containing polymer having a backbonestructure where two aromatic rings are bound to a quaternary carbon atomthat is a constituent atom of another cyclic moiety in the main chainand including a carboxylic acid group (—COOH) (for example, being boundto the main chain).

In the multiple aromatic ring-containing polymer, the backbone structuremay include a repeating unit represented by Chemical Formula B:

wherein

* indicates a portion that is linked to an adjacent atom of the mainchain of the binder,

Z¹ is a linking moiety represented by any one of Chemical Formulae B-1to B-6, and in Chemical Formulae B-1 to B-6,

wherein

R^(a) is hydrogen, an ethyl group, C₂H₄Cl, C₂H₄OH, CH₂CH═CH₂, or aphenyl group,

wherein * indicates a portion that is linked to an adjacent atom.

The multiple aromatic ring-containing polymer may include a repeatingunit represented by Chemical Formula C:

wherein

Z¹ is a linking moiety represented by any one of Chemical Formulae B-1to B-6,

L is a single bond, a C1 to C10 alkylene, a C1 to C10 alkylene having asubstituent including a carbon-carbon double bond, a C1 to C10 oxyalkylene, or a C1 to C10 oxy alkylene having a substituent including acarbon-carbon double bond,

A is —NH—, —O—, or a C1 to C10 alkylene,

each of R¹ and R² is independently hydrogen, a halogen, or a substitutedor unsubstituted C1 to C20 alkyl group,

m1 and m2 are independently an integer ranging from 0 to 4,

Z² is a C6 to C40 aromatic organic group, and

each of * and *′ indicate a portion that is linked to an adjacent atom.

In Chemical Formula C, Z² may be any one of Chemical Formula C-1,Chemical Formula C-2, and Chemical Formula C-3:

wherein * indicates a portion that is linked to an adjacent carbonylcarbon,

wherein * indicates a portion that is linked to an adjacent carbonylcarbon,

wherein

* indicates a portion that is linked to an adjacent carbonyl carbon,

L is a single bond, —O—, —S—, —C(═O)—, —CH(OH)—, —S(═O)₂—, —Si(CH₃)₂—,—(CH₂)_(p)— (wherein 1≦p≦10), —(CF₂)_(p)— (wherein 1≦q≦10), —CR₂—(wherein R is independently hydrogen, a C1 to C10 aliphatic hydrocarbongroup, a C6 to C20 aromatic hydrocarbon group, or a C6 to C20 alicyclichydrocarbon group), —C(CF₃)₂—, —C(CF₃)(C₆H₅)—, or —C(═O)NH—.

The multiple aromatic ring-containing polymer may include a structuralunit represented by Chemical Formula D:

wherein

each of R¹ and R² is independently hydrogen or a substituted orunsubstituted (meth)acryloyloxyalkyl group,

each of R³ and R⁴ is independently hydrogen, a halogen, or a substitutedor unsubstituted C1 to C20 alkyl group,

Z¹ is a moiety selected from linking moieties represented by ChemicalFormulae B-1 to B-6,

Z² is an aromatic organic group such as the moieties set forth above,

m1 and m2 are independently an integer ranging from 0 to 4, and

* indicates a portion that is linked to an adjacent atom.

The multiple aromatic ring-containing polymer may be an acid adduct ofbisphenol fluorene epoxy acrylate. For example, the bisphenol fluoreneepoxy acrylate may be prepared by reacting4,4-(9-fluorenylidene)-diphenol and epichlorohydrine to obtain an epoxycompound having a fluorene moiety, and the epoxy compound is reactedwith an acrylic acid to obtain a fluorenyl epoxy acrylate, which is thenfurther reacted with biphenyl dianhydride and/or phthalic anhydride. Theaforementioned reaction scheme may be summarized as below:

The multiple aromatic ring-containing polymer may include a functionalgroup represented by Chemical Formula E at one or both terminal ends:

wherein

* indicates a portion that is linked to an adjacent atom, and

Z³ is a moiety represented by one of Chemical Formulae E-1 to E-7:

wherein

each of R^(b) and R^(c) is independently hydrogen, a substituted orunsubstituted C1 to C20 alkyl group, an ester group, or an ether group,and

* indicates a portion that is linked to an adjacent atom.

wherein R^(d) is O, S, NH, a substituted or unsubstituted C1 to C20alkylene group, a C1 to C20 alkylamine group, or a C2 to C20alkenylamine group.

The multiple aromatic ring-containing polymer may be synthesized by aknown method or is commercially available (e.g., from Nippon SteelChemical Co., Ltd.).

As non-limiting examples, the multiple aromatic ring-containing polymermay include a reaction product of a fluorene compound selected from9,9-bis(4-hydroxyphenyl)fluorene, 9,9-bis(4-aminophenyl)fluorene,9,9-bis[4-(glycidyloxy)phenyl]fluorene, and9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene with an appropriate compoundcapable of reacting with the fluorene compound (e.g., an aromaticdianhydride selected from 9,9-bis-(3,4-dicarboxyphenyl)fluorenedianhydride, pyromellitic dianhydride (PDMA), biphenyltetracarboxylicdianhydride (BPDA), benzophenone tetracarboxylic dianhydride, andnaphthalene tetracarboxylic dianhydride, a C2 to C30 diol compound,epichlorohydrine, or the like). The fluorene compound, dianhydrides, adiol compound, and the like are commercially available, and the reactionconditions therebetween are known in the art.

The carboxylic acid group-containing binder may have a molecular weightof greater than or equal to about 1,000 g/mol, for example, greater thanor equal to about 2,000 g/mol, greater than or equal to about 3,000g/mol, or greater than or equal to about 5,000 g/mol. The carboxylicacid group-containing binder may have a molecular weight of less than orequal to about 100,000 g/mol, for example, less than or equal to about50,000 g/mol. While not wishing to be bound by theory, it is understoodthat within the foregoing ranges, more improved developability may beensured.

In the photosensitive composition, an amount of the carboxylic acidgroup-containing binder may be greater than or equal to about 0.5 wt %,for example, greater than or equal to about 1 wt %, greater than orequal to about 5 wt %, greater than or equal to about 10 wt %, greaterthan or equal to about 15 wt %, or greater than or equal to about 20 wt% based on the total weight of the composition. An amount of thecarboxylic acid group-containing binder may be less than or equal toabout 40 wt %, for example, less than or equal to about 30 wt % based onthe total weight of the composition. In an embodiment, an amount of thecarboxylic acid group-containing binder may be 5 to 40 wt % based on thetotal weight of solids (i.e., non-volatiles) of the composition. Whilenot wishing to be bound by theory, it is understood that within theaforementioned range, appropriate developability and improvedprocessability may be accomplished in a subsequent pattern formingprocess while ensuring dispersibility of the quantum dots.

A photosensitive composition of an embodiment includes a reactivecompound having at least two thiol groups.

The reactive compound may have a structure of Chemical Formula 6:

wherein

R¹ is hydrogen, a substituted or unsubstituted C1 to C30 linear orbranched alkyl group, a substituted or unsubstituted C6 to C30 arylgroup, a substituted or unsubstituted C7 to C30 arylalkyl group, asubstituted or unsubstituted C3 to C30 heteroaryl group, a substitutedor unsubstituted C4 to C30 heteroarylalkyl group, a substituted orunsubstituted C3 to C30 cycloalkyl group, a substituted or unsubstitutedC3 to C30 heterocycloalkyl group, a C1 to C10 alkoxy group, a hydroxygroup, —NH₂, a substituted or unsubstituted C1 to C30 amine group(—NRR′, wherein R and R′ are independently hydrogen or a C1 to C30linear or branched alkyl group); an isocyanate group; a halogen; —ROR′(wherein R is a substituted or unsubstituted C1 to C20 alkylene groupand R′ is hydrogen or a C1 to C20 linear or branched alkyl group); anacyl halide (—RC(═O)X, wherein R is a substituted or unsubstituted C1 toC20 alkylene group and X is a halogen), —C(═O)OR′ (wherein R′ ishydrogen or a C1 to C20 linear or branched alkyl group), —CN,—C(═O)ONRR′ (wherein R and R′ are independently hydrogen or a C1 to C20linear or branched alkyl group), or a combination thereof,

L₁ is a carbon atom, a substituted or unsubstituted C1 to C30 alkylenegroup, a substituted or unsubstituted C6 to C30 cycloalkylene group, asubstituted or unsubstituted C6 to C30 arylene group, or a substitutedor unsubstituted C6 to C30 heteroarylene group, wherein at least onemethylene (—CH₂—) of the substituted or unsubstituted C1 to C30 alkylenegroup may be replaced by sulfonyl (—S(═O)₂—), carbonyl (—C(═O)—), ether(—O—), sulfide (—S—), sulfoxide (—S(═O)—), ester (—C(═O)O—), amide(—C(═O)NR—) (wherein R is hydrogen or a C1 to C10 alkyl group), or acombination thereof,

Y₁ is a single bond, a substituted or unsubstituted C1 to C30 alkylenegroup, a substituted or unsubstituted C2 to C30 alkenylene group, or aC1 to C30 alkylene group or a C2 to C30 alkenylene group wherein atleast one methylene (—CH₂—) is replaced by sulfonyl (—S(═O)₂—), carbonyl(—C(═O)—), ether (—O—), sulfide (—S—), sulfoxide (—S(═O)—), ester(—C(═O)O—), amide (—C(═O)NR—) (wherein R is hydrogen or a C1 to C10linear or branched alkyl group), imine (—NR—) (wherein R is hydrogen ora C1 to C10 linear or branched alkyl group), or a combination thereof,

m is an integer of 1 or more,

k1 is 0 or an integer of 1 or more,

k2 is an integer of 1 or more, and

the sum of m and k2 is an integer of 3 or more,

provided that m does not exceed the valence of Y₁ when Y₁ is not asingle bond, and

provided that the sum of k1 and k2 does not exceed the valence of L₁.

The reactive compound may include a compound of Chemical Formula 6-1:

wherein

L₁′ is carbon, a substituted or unsubstituted C2 to C20 group derivedfrom an alkane, a substituted or unsubstituted C6 to C30 group derivedfrom an arene, a substituted or unsubstituted C3 to C30 group derivedfrom a heteroarene, a substituted or unsubstituted C3 to C30 groupderived from a cycloalkane, or a substituted or unsubstituted C3 to C30group derived from a heterocycloalkane,

Y_(a) to Y_(d) are independently a single bond, a substituted orunsubstituted C1 to C30 alkylene group, a substituted or unsubstitutedC2 to C30 alkenylene group, or a C1 to C30 alkylene group or a C2 to C30alkenylene group wherein at least one methylene (—CH₂—) is replaced bysulfonyl (—S(═O)₂—), carbonyl (—C(═O)—), ether (—O—), sulfide (—S—),sulfoxide (—S(═O)—), ester (—C(═O)O—), amide (—C(═O)NR—) (wherein R ishydrogen or a C1 to C10 linear or branched alkyl group), imine (—NR—)(wherein R is hydrogen or a C1 to C10 linear or branched alkyl group),or a combination thereof, and

each of R_(a) to R_(d) is independently R¹ of Chemical Formula 1 or SH,provided that at least two of them are SH.

The reactive compound may react with a photopolymerizable monomer (whichwill be described in detail below) without an adverse effect on thedispersion of quantum dots, and thereby prevent the heat treatment(e.g., post-baking), which is accompanied by the photoresist process,from deteriorating the luminous efficiency of the quantum dots dispersedin the pattern. Without wishing to be bound by any theory, it isbelieved that the reactive compound may allow the polymer to form adenser network by further reacting with the photopolymerizable monomerdescribed later. In addition, the reactive compound may provide a bondbetween the quantum dots and the photopolymerizable monomers to ensurethe dispersion and the stability of the quantum dots in the composite. Apattern formed from the photosensitive resin composition including thereactive compound may enhance the light emitting properties (such as aproperty of maintaining the blue-light conversion rate), for example, byat least about 2 times in comparison with the composite without thereactive compound. In some embodiments, the photosensitive compositionmay maintain a blue light conversion rate of greater than or equal toabout 40% of the initial value when it is developed by an alkali aqueoussolution and then dried and heated at 180° C. for 30 min.

The reactive compound may include a dithiol compound, a trithiolcompound, a tetrathiol compound, or a combination thereof. For example,the reactive compound may include glycol di-3-mercaptopropionate, glycoldimercaptoacetate, trimethylolpropane tris(3-mercaptopropionate),pentaerythritol tetrakis(3-mercaptopropionate), pentaerythritoltetrakis(2-mercaptoacetate), 1,6-hexanedithiol, 1,3-propanedithiol,1,2-ethanedithiol, polyethylene glycol dithiol including 1 to 10ethylene glycol repeating units, or a combination thereof. In thephotosensitive composition, an amount of the reactive compound may begreater than or equal to about 0.1 wt %, for example, greater than orequal to about 0.5 wt %, or greater than or equal to about 1 wt % basedon the total weight of the composition. The amount of the reactivecompound may be less than or equal to about 40 wt %, for example, lessthan or equal to about 30 wt %, less than or equal to about 25 wt %,less than or equal to about 20 wt %, less than or equal to about 19 wt%, less than or equal to about 18 wt %, less than or equal to about 17wt %, less than or equal to about 16 wt %, less than or equal to about15 wt %, less than or equal to about 14 wt %, less than or equal toabout 13 wt %, less than or equal to about 12 wt %, less than or equalto about 10 wt %, less than or equal to about 9 wt %, less than or equalto about 8 wt %, less than or equal to about 7 wt %, less than or equalto about 6 wt %, less than or equal to about 5 wt % based on the totalweight of the composition.

The photosensitive composition according to an embodiment includes aphotopolymerizable monomer having at least one (e.g., two, three, four,five, six, or more) carbon-carbon double bond (e.g., an acrylate groupor a methacrylate group). Types of the photopolymerizable monomer arenot particularly limited as long as they include a carbon-carbon doublebond and may be polymerized by light. For example, thephotopolymerizable monomer may be a monomer or an oligomer that may beused in a photosensitive composition. The photopolymerizable monomer mayinclude a monofunctional or multi-functional ester of (meth)acrylic acidhaving at least one ethylenic unsaturated double bond. For example, thephotopolymerizable monomer may include a vinyl monomer, an unsaturatedethylenic oligomer, a homopolymer thereof, a copolymer of theunsaturated ethylenic oligomer and an ethylenic unsaturated monomer, ora combination thereof. Examples of the photopolymerizable monomer mayinclude, but are not limited to, alkyl (meth)acrylate, ethylene glycoldi(meth)acrylate, triethylene glycol di(meth)acrylate, diethylene glycoldi(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanedioldi(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritoldi(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritoltetra(meth)acrylate, dipentaerythritol di(meth)acrylate,dipentaerythritol tri(meth)acrylate, dipentaerythritolpenta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, bisphenol Aepoxyacrylate, bisphenol A di(meth)acrylate, trimethylolpropanetri(meth)acrylate, ethylene glycol monomethyl ether (meth)acrylate,novolacepoxy (meth)acrylate, diethylene glycol di(meth)acrylate,triethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate,tris(meth)acryloyloxyethyl phosphate, and the like. Thephotopolymerizable monomer of the embodiments may include adi(meth)acrylate compound, a tri(meth)acrylate compound, atetra(meth)acrylate compound, a penta(meth)acrylate compound, ahexa(meth) acrylate compound, or a combination thereof.

In the photosensitive composition, the amount of the photopolymerizablemonomer may be greater than or equal to about 0.5 wt %, for example,greater than or equal to about 1 wt %, or greater than or equal to about2 wt % with respect to a total amount of the composition. The amount ofthe photopolymerizable monomer may be less than or equal to about 30 wt%, for example less than or equal to about 25 wt %, less than or equalto about 20 wt %, the amount of the photopolymerizable monomer may be 10wt % with respect to a total amount of the composition.

The photosensitive composition may include a photopolymerizationinitiator. Types of the photopolymerization initiator are notparticularly limited, and may be selected appropriately. For example,the available photopolymerization initiator may include a triazinecompound, an acetophenone compound, a benzophenone compound, athioxanthone compound, a benzoin compound, an oxime compound, or acombination thereof, but it is not limited thereto.

Examples of the triazine compound may include2,4,6-trichloro-s-triazine,2-phenyl-4,6-bis(trichloromethyl)-s-triazine,2-(3′,4′-dimethoxystyryl)-4,6-bis(trichloromethyl)-s-triazine,2-(4′-methoxynaphthyl)-4,6-bis(trichloromethyl)-s-triazine, 2-(p-methoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine,2-(p-tolyl)-4,6-bis(trichloromethyl)-s-triazine,2-biphenyl-4,6-bis(trichloromethyl)-s-triazine,2,4-bis(trichloromethyl)-6-styryl-s-triazine,2-(naphth-1-yl)-4,6-bis(trichloromethyl)-s-triazine,2-(4-methoxynaphth-1-yl)-4,6-bis(trichloromethyl)-s-triazine,2,4-trichloromethyl(piperonyl)-6-triazine, and 2,4-trichloromethyl(4′-methoxy styryl)-6-triazine, but are not limited thereto.

Examples of the acetophenone compound may be 2,2′-diethoxyacetophenone,2,2′-dibutoxyacetophenone, 2-hydroxy-2-methylpropiophenone,p-t-butyltrichloroacetophenone, p-t-butyldichloro acetophenone,4-chloroacetophenone, 2,2′-dichloro-4-phenoxyacetophenone,2-methyl-1-(4-(methylthio)phenyl)-2-morpholinopropan-1-one,2-benzyl-2-dimethylamino-1-(4-morpholinophenyI)-butan-1-one, and thelike, but are not limited thereto.

Examples of the benzophenone compound may be benzophenone, benzoylbenzoate, benzoyl methyl benzoate, 4-phenylbenzophenone,hydroxybenzophenone, acrylated benzophenone,4,4′-bis(dimethylamino)benzophenone, 4,4′-dichlorobenzophenone,3,3′-dimethyl-2-methoxybenzophenone, and the like, but are not limitedthereto.

Examples of the thioxanthone compound may be thioxanthone,2-methylthioxanthone, 2-isopropylthioxanthone, 2,4-diethylthioxanthone,2,4-diisopropylthioxanthone, 2-chlorothioxanthone, and the like, but arenot limited thereto.

Examples of the benzoin compound may include benzoin, benzoin methylether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutylether, benzyl dimethyl ketal, and the like, but are not limited thereto.

Examples of the oxime compound may be2-(o-benzoyloxime)-1-[4-(phenylthio)phenyl]-1,2-octanedione,1-(o-acetyloxime)-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone,and the like, but are not limited thereto.

The photopolymerization initiator may also be a carbazole compound, adiketone compound, a sulfonium borate compound, a diazo compound, adi-imidazole compound, and the like, in addition to thephotopolymerization initiators.

In the photosensitive composition, an amount of the photoinitiator maybe greater than or equal to about 0.01 wt %, for example, greater thanor equal to about 0.1 wt %, or greater than or equal to about 1 wt %,based on the total weight of the composition. The amount of thephotoinitiator may be less than or equal to about 10 wt %, for example,less than or equal to about 5 wt %, based on the total weight of thecomposition. In an embodiment, the amount of the photoinitiator may beabout 0.05 to about 10 wt % based on the total weight of solids (i.e.,non-volatiles) of the composition. While not wishing to be bound bytheory, it is understood that within the aforementioned ranges, adesirable pattern may be formed.

If desired, the photosensitive composition may further include variousadditives such as a light diffusing agent, a leveling agent, or acoupling agent in addition to the aforementioned components. The amountof the additive is not particularly limited, and may be selected withinan appropriate range wherein the additive does not cause an adverseeffect on the photosensitive composition and the pattern obtainedtherefrom.

The light diffusing agent may increase a refractive index of thecomposition in order to increase a chance of the incident light to meetwith quantum dots. The light diffusing agent may include inorganic oxideparticles such as alumina, silica, zirconia, titanium oxideparticulates, or zinc oxide, and metal particles such as gold, silver,copper, or platinum, but is not limited thereto.

The leveling agent is aimed to prevent stains or spots and to improveplanarization and leveling characteristics of a film, and examplesthereof may include the following but are not limited thereto.

A fluorine-containing leveling agent may include commercial products,for example BM-1000® and BM-1100® of BM Chemie Inc.; MEGAFACE F 142D®, F172®, F 173®, and F 183® of Dainippon Ink Kagaku Kogyo Co., Ltd.;FC-135®, FC-170C®, FC-430®, and FC-431® of Sumitomo 3M Co., Ltd.;SURFLON S-112®, SURFLON S-113®, SURFLON S-131®, SURFLON S-141®, andSURFLON S-145® of Asahi Glass Co., Ltd.; and SH-28PA®, SH-190®, SH-193®,SZ-6032®, SF-8428®, and the like of Toray Silicone Co., Ltd.

Types and amounts of the additives may be adjusted as necessary.

The coupling agent is aimed to increase adherence with respect to thesubstrate and examples thereof may include a silane-containing couplingagent. Examples of the silane-containing coupling agent may be vinyltrimethoxysilane, vinyl tris(2-methoxyethoxysilane),3-glycidoxypropyltrimethoxysilane,2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane,3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane,3-methacryloxylpropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane,and the like.

The photosensitive composition may include a solvent. The solvent may beincluded in the quantum dot dispersion. An amount of the solvent may bedetermined depending on the amounts of the above main components (i.e.,the organic ligand-containing quantum dots, the COOH group-containingbinder, the photopolymerizable monomer combination, and thephotoinitiator), and additives. The composition may include the solventin such an amount that the remaining amount of the composition otherthan the amounts of the solid (i.e., non-volatiles) components is theamount of the solvent. The solvent may be selected appropriatelyconsidering its affinity for other components (e.g., the binder, thephotopolymerizable monomer, the photoinitiator, and other additives),its affinity for the alkali developing solution, and its boiling point.Examples of the solvent may be:

ethyl 3-ethoxy propionate;

an ethylene glycol such as ethylene glycol, diethylene glycol, orpolyethylene glycol;

a glycol ether such as ethylene glycol monomethyl ether, ethylene glycolmonoethyl ether, diethylene glycol monomethyl ether, ethylene glycoldiethyl ether, and diethylene glycol dimethyl ether;

glycol ether acetates such as ethylene glycol acetate, ethylene glycolmonoethyl ether acetate, diethylene glycol monoethyl ether acetate, anddiethylene glycol monobutyl ether acetate;

a propylene glycol such as propylene glycol; propylene glycol etherssuch as propylene glycol monomethyl ether, propylene glycol monoethylether, propylene glycol monopropyl ether, propylene glycol monobutylether, propylene glycol dimethyl ether, dipropylene glycol dimethylether, propylene glycol diethyl ether, and dipropylene glycol diethylether;

propylene glycol ether acetates such as propylene glycol monomethylether acetate and dipropylene glycol monoethyl ether acetate;

amides such as N-methylpyrrolidone, dimethyl formamide, and dimethylacetamide;

ketones such as methyl ethyl ketone (MEK), methyl isobutyl ketone(MIBK), and cyclohexanone;

petroleum products such as toluene, xylene, and solvent naphtha;

esters such as ethyl acetate, butyl acetate, and ethyl lactate;

ethers such as diethyl ether, dipropyl ether, and dibutyl ether; and

any combinations thereof.

A method of preparing a photosensitive composition according to anembodiment includes:

dissolving the COOH containing binder in the solvent to prepare a bindersolution;

dispersing a plurality of quantum dots having an organic ligand bound toa surface thereof in the binder solution to obtain a quantum dot-binderdispersion; and

combining the quantum dot-binder dispersion with at least one selectedfrom a reactive compound, a photoinitiator, a photopolymerizablemonomer, and a solvent.

A combining manner is not particularly limited, and may be appropriatelyselected. For example, each component may be combined sequentially orsimultaneously.

The method may further include selecting quantum dots including anorganic ligand bonded to the surface, and selecting a binder capable ofdispersing the quantum dots (e.g., a carboxylic acid group-containingbinder). In the step of selecting the binder, the binder may be acarboxylic acid group-containing binder. The carboxylic acidgroup-containing binder may be a copolymer of a monomer combinationincluding a first monomer having a carboxylic acid group and acarbon-carbon double bond and a second monomer having a carbon-carbondouble bond and a hydrophobic moiety and not having a carboxylic acidgroup. A chemical structure and an acid value of the copolymer may beconsidered in this step.

Details of the quantum dots, the carboxylic acid group-containingbinder, the photopolymerizable monomer, the photoinitiator, and thequantum dot dispersion are the same as set forth above.

The photosensitive composition may be developable with an alkalineaqueous solution, and thus a quantum dot-polymer composite pattern maybe patterned from the photosensitive composition without using anorganic solvent developing solution.

A non-limiting method of forming a pattern is explained referring toFIG. 1.

First, the photosensitive composition is coated on a predeterminedsubstrate (e.g., a glass substrate or a glass substrate coated with apredetermined thickness of SiN_(x) (protective layer) (e.g., 500 to1,500 Angstroms (Å) of the protective layer)) in an appropriate mannersuch as spin coating, slit coating, and the like to form a film of apredetermined thickness (e.g., a thickness of 3 to 30 micrometers, μm).The formed film may be pre-baked, if desired. The specific conditions ofpre-baking such as temperature, time, and atmosphere are known in theart and may be appropriately selected.

The formed (or optionally, pre-baked) film is exposed to light of apredetermined wavelength under a mask having a predetermined pattern.The wavelength and the intensity of light may be selected depending onthe types and the amounts of the photoinitiator, the types and theamounts of quantum dots, or the like.

The exposed film is treated with an alkali developing solution, andthereby the unexposed region in the film is dissolved to provide adesirable pattern. The obtained pattern may be post-baked, if desired,to improve crack resistance and solvent resistance of the pattern, forexample, at a temperature of about 150° C. to about 230° C. for apredetermined time (e.g., greater than or equal to about 10 min orgreater than or equal to about 20 min). Even after the performing of thepost-bake process, the pattern obtained from the photosensitivecomposition may show improved thermal stability, so that the lightconversion rate may be maintained at 30% or higher (e.g., 40% or higher)of the initial value.

When a quantum dot-polymer composite obtained from the photosensitivecomposition is used as a color filter, two or three types ofphotosensitive compositions each including red quantum dots, greenquantum dots, (or optionally, blue quantum dots) are prepared, and thepatterning process is repeated as many times as necessary (e.g., twotimes or three times) for each composition to provide a quantumdot-polymer composite having a desirable pattern.

Another embodiment provides a quantum dot-polymer composite, whichincludes:

a matrix including a carboxylic acid group (—COOOH)-containing polymerand a polymerization product of a photopolymerizable monomer having acarbon-carbon double bond and a reactive compound having at least twothiol groups; and

a plurality of quantum dots;

wherein the COOOH-containing polymer includes a copolymer of a monomercombination including a first monomer having a carboxylic acid group anda carbon-carbon double bond and a second monomer having a carbon-carbondouble bond and a hydrophobic moiety and not having a carboxylic acidgroup; and

the plurality of quantum dots are dispersed (e.g., separated from oneanother) in the matrix (e.g., without agglomeration).

The composite may be a pattern. The quantum dot may include an organicligand bound to a surface thereof.

Details of the quantum dots, the binder, the photopolymerizable monomer,and the like are the same as set forth above. The copolymer may be alinear polymer. The photopolymerizable monomer may include a monomerhaving at least three (meth)acrylate groups and the polymerizationproduct may include a crosslinked polymer.

In some embodiments, a color filter includes the quantum dot-polymercomposite or a pattern thereof. In another embodiment, a display deviceincludes the quantum dot-polymer composite or a pattern thereof. Thedisplay device may be a liquid crystal display device.

Referring to FIG. 13 and FIG. 14, in a non-limiting embodiment, theliquid crystal display includes: a liquid crystal panel 200, an opticalelement 300 (e.g., a polarizing plate) that is disposed on and/or belowthe liquid crystal panel 200, and a back light unit that is disposedbelow the lower optical element 300 and includes a blue light emittingsource. The liquid crystal panel 200 may include a lower substrate 210,an upper substrate 240, a liquid crystal layer 220 interposed betweenthe upper and the lower substrates. The device include a color filter230 disposed on a top surface or a bottom surface of the upper substrate240. The color filter includes the aforementioned quantum dot-polymercomposite or a pattern thereof.

The back light unit may include a light source 110 and optionally alight guide panel 120.

A wire plate 211 is disposed on an internal surface, e.g., a topsurface, of the lower substrate 210. The wire plate 211 may include aplurality of gate wires (not shown) and data wires (not shown), a thinfilm transistor disposed adjacent to a crossing region of gate wires anddata wires, and a pixel electrode for each pixel area, but is notlimited thereto. In an embodiment, for example, pixel areas may bedefined by the gate and data wires. The wire plate may have anystructure or feature well-known in the art, and are not particularlylimited.

The liquid crystal layer 220 may be disposed on the wire plate 211. Theliquid crystal layer 220 may include alignment layers 221 on and underthe layer 220 to initially align the liquid crystal material includedtherein. The liquid crystal material and the alignment layer may haveany structure or feature well-known in the art (e.g., liquid crystalmaterial, alignment layer material, method of forming liquid crystallayer, thickness of liquid crystal layer, or the like) and are notparticularly limited.

The optical element 300 may be a member for maintaining polarization oflight emitted from the photoluminescent color filter layer. In anembodiment, for example, the optical element 300 may be a polarizer. Ablack matrix 241 having an opening defined therethrough is disposed onthe upper substrate 240, e.g., the bottom surface of the upper substrate240, to cover a thin film transistor and a gate line, a data line, orthe like of the wire plate disposed on the lower substrate 210. Aphotoluminescent color filter layer 230 including a first color filter(R) for emitting red light, a second color filter (G) for emitting greenlight, and/or a third color filter (B) for (emitting or transmitting)blue light may be disposed on the black matrix 241 and in the opening ofthe black matrix 241. In an exemplary embodiment, the black matrix 241may have a lattice shape. A transparent common electrode 231 may bedisposed on the photoluminescent color filter layer.

A liquid crystal display (hereinafter, LCD) is a display in whichpolarized light passes through a liquid crystal and then anabsorption-type color filter to express a color. The LCD often hasdrawbacks such as a narrow viewing angle and low luminance due to a lowlevel of light transmittance of the absorption-type color filter. Forexample, in the conventional LCD including the absorption-type colorfilter, the light (e.g. the white light) provided from the back lightunit passes through the color filter to provide red, green, and bluelight, and thus the intensity of light is inevitably decreased by onethird. In contrast, in the display of the embodiments, the blue lightfrom the back light unit passes through the color filter to providelight having a desired color without the aforementioned light lossoccurring in the conventional LCD including the absorption-type colorfilter. Therefore, the display of the embodiments may show a luminanceefficiency that is at least about three times greater than that of thatconventional LCD. In addition, as the display of the embodimentsincludes the photoluminescent color filter, it may emit light atsubstantially the same intensity in all directions, allowing a widerviewing angle.

Hereinafter, the embodiments are illustrated in more detail withreference to examples. However, the present disclosure is not limitedthereto.

EXAMPLES Example 1 [1] Preparation of Quantum Dot-Binder Dispersion

A chloroform dispersion of red light emitting or green light emittingquantum dots (InP/ZnS) including oleic acid as a hydrophobic organicligand bonded to a surface thereof is prepared.

The chloroform dispersion including 50 grams (g) of quantum dots (red)including oleic acid as a hydrophobic organic ligand bonded to a surfacethereof is mixed with 100 g of a binder (a four membered copolymer ofmethacrylic acid, benzyl methacrylate, hydroxyethyl methacrylate, andstyrene, acid value: 130 milligrams (mg) per gram of KOH (mg KOH/g),molecular weight: 8,000, acrylic acid:benzyl methacrylate:hydroxyethylmethacrylate:styrene (molar ratio)=61.5%:12%:16.3%:10.2%) solution(polypropylene glycol monomethyl ether acetate having a concentration of30 percent by weight, wt %) to provide a quantum dot-binder dispersion.

A photographic image of the dispersion thus prepared is shown in FIG. 2.FIG. 2 confirms that quantum dots are uniformly dispersed in the quantumdot-binder dispersion.

[2] Preparation of the Photosensitive Composition

To the quantum dot-binder dispersion, 10 g of glycoldi-3-mercaptopropionate (hereinafter, 2T) having the followingstructure, 100 g of hexaacrylate having the following structure (as aphotopolymerizable monomer), 1 g of an oxime ester compound (as aninitiator), 30 g of TiO₂ (as a light diffusing agent), and 300 g ofPGMEA (as a solvent) are added to obtain a photosensitive composition.

It is confirmed that the photosensitive composition thus prepared mayform a dispersion without showing any noticeable agglomeration due tothe addition of the quantum dots.

[3] Formation of Quantum Dot-Polymer Composite Pattern

The photosensitive composition obtained from item [2] is spin-coated ona glass substrate at 150 revolutions per minute (rpm) for 5 seconds (s)to provide a film. The obtained film is pre-baked at 100° C. for 2minutes (min). The pre-baked film is irradiated with light (wavelength:365 nanometers (nm), intensity: 60 millijoules, mJ) for 1 s under a maskhaving a predetermined pattern and developed by a potassiumhydroxide-diluted aqueous solution (concentration: 0.043%) for 50 s toprovide a pattern.

An optical microscope image of the obtained pattern is shown in FIG. 3,and a photographic image of the cross-section of the obtained pattern isshown in FIG. 11.

The results of FIG. 3 confirm that the composition of Example 1 may forma pattern (line width: 100 micrometers, um) including quantum dotsdispersed in a polymer. When the obtained pattern is irradiated withblue light (wavelength: 450 nm), red light is emitted from the pattern.

[4] Luminous Stability Test after the Post-Bake Treatment

The obtained pattern is subjected to 30 min of heating at 180° C. threetimes. For each time, the blue light conversion rate is measured and theresults are compiled in Table 1.

Example 2

A photosensitive composition is prepared to form a pattern in accordancewith the same procedure as in Example 1, except that trimethylolpropanetris(3-mercaptopropionate) (3T) having the following structure is used,and the blue light conversion rate of the obtained pattern is measuredand the results are compiled in Table 1.

Example 3

A photosensitive composition is prepared to form a pattern in accordancewith the same procedure as in Example 1, except that pentaerythritoltetrakis(3-mercaptopropionate) (4T) having the following structure isused, and the blue light conversion rate of the obtained pattern ismeasured and the results are compiled in Table 1.

Example 4

A photosensitive composition is prepared to form a pattern in accordancewith the same procedure as in Example 1, except that pentaerythritoltetrakis(2-mercaptopropionate) (PE-TSA) having the following structureis used, and the blue light conversion rate of the obtained pattern ismeasured and the results are compiled in Table 1.

Comparative Example 1

A photosensitive composition is prepared to form a pattern in accordancewith the same procedure as in Example 1, except that no reactivecompound is used and the blue light conversion rate of the obtainedpattern is measured, and the results are compiled in Table 1 and FIG. 5.

TABLE 1 Blue light conversion rate (%) Ratio of maintaining the initialblue Exposure & light Prebake development First post bake conversion(PrB) (ExP) (PoB) Second PoB Third PoB rate Example 1 27.1 24.6 15 14.613.9 53.1 Example 2 25 22.4 13.1 11.9 11.9 46.1 Example 3 30.9 24.7 14.713.8 13 41.6 Example 4 26.7 23.4 14.4 13.7 13.3 49.5 Comparative 24.921.3 7.7 6.7 5.5 18.7 Example 1

The results of Table 1 confirm that the quantum dot-polymer patterns ofExamples 1 to 4 may maintain its blue light conversion rate at least 30%(for example at least 40% or higher) of the initial blue lightconversion rate after three times of heating at a temperature of 180° C.

Comparative Example 2

100 g of the same binder solution as in Example 1, 100 g of the samephotopolymerizable monomer as in Example 1 (a hexaacrylate compound), 1g of the same photoinitiator as in Example 1, 10 g of glycoldi-3-mercaptopropionate (hereinafter, 2T), and 300 g of PGMEA are mixedto prepare a mixture.

To the obtained mixture, the same chloroform solution of the quantumdots as in Example 1 is added to prepare a photosensitive composition.

The photographic image of the obtained photosensitive composition isshown in FIG. 6. The results of FIG. 6 confirm that when the samequantum dot solution as in Example 1 is mixed with the same amount andthe same type of binder, photopolymerizable monomer, photoinitiator, andsolvent as in Example 1, the agglomeration of the quantum dots issignificant, and thus a composition including the quantum dots dispersedtherein cannot be obtained.

Comparative Example 3

A photosensitive composition is prepared to form a pattern in accordancewith the same procedure as in Example 1, except that 100 g of the bindersolution (concentration 30 wt %, polypropylene glycol monomethyl etheracetate) includes a binder resin having the same repeating units and anacid value of 30 mg KOH/g, and no reactive compound is used.

The photographic image of the prepared composition is shown in FIG. 7.

FIG. 7 confirms that the aforementioned binder solution cannot dispersethe quantum dots.

The photographic image of the prepared pattern is shown in FIG. 8. FIG.8 confirms that when the quantum dots fail to be uniformly dispersed inthe photosensitive composition, a desired pattern of the quantumdot-polymer composite cannot be obtained.

Comparative Example 4

A photosensitive composition is prepared to form a pattern in accordancewith the same procedure as in Example 1, except that 100 g of the bindersolution (concentration 30 wt %, polypropylene glycol monomethyl etheracetate) includes a binder resin having the same repeating units and anacid value of 60 mg KOH/g, and no reactive compound is used.

It is confirmed that in the prepared composition, the quantum dots arenot dispersed well and are significantly agglomerated, and by using theprepared composition, a desired pattern of the quantum dot polymercomposite cannot be obtained.

Example 5

A photosensitive composition is prepared to form a pattern in accordancewith the same procedure as in Example 1, except that 100 g of greenlight emitting quantum dots and 30 g of TiO₂ are used. The blue lightconversion rate of the formed pattern is measured and the results areshown in FIG. 9.

Comparative Example 5

A photosensitive composition is prepared to form a pattern in accordancewith the same procedure as in Comparative Example 1, except that 100 gof the quantum dots is used and 30 g of TiO₂ is added. The blue lightconversion rate of the formed pattern is measured and the results areshown in FIG. 9.

The results of FIG. 9 confirm that after three 30 min heat-treatments at180° C., the quantum dot polymer composite pattern prepared from thecomposition including the reactive compound may show a maintenance ratioof the blue light conversion rate that is three times that of thequantum dot polymer composite pattern prepared from the composition withno reactive compound.

Examples 6 to 8 and Comparative Example 6 Stability Test Depending onthe Amount of the Quantum Dots

A photosensitive composition is prepared to form a pattern in accordancewith the same procedure as in Example 1, except that green lightemitting quantum dots (InP/ZnS) are used and the amount of the reactivecompound, 2T, is changed to 0 g (Comparative Example 6), 5 g (Example6), 10 g (Example 7), and 30 g (Example 8), respectively. The blue lightconversion rate for each of the prepared quantum dot polymer compositepatterns is measured, and the results are shown in FIG. 10.

The results of FIG. 10 confirm that after three 30 min heat-treatmentsat 180° C., the quantum dot polymer composite pattern prepared from thecomposition including the reactive compound may show a maintenance ratioof the blue light conversion rate that is at least two times higher thanthat of the quantum dot polymer composite pattern prepared from thecomposition with no reactive compound.

Comparative Examples 7 to 9

A photosensitive composition is prepared to form a pattern in accordancewith the same procedure as in Example 1, except that no reactivecompound is used (Comparative Example 1), or as a reactive compound, 10g of a compound having one thiol group such as octadecyl thiol, methyl3-mercaptopropionate (1T(H), Comparative Example 7), 1-dodecanethiol(1T(D) Comparative Example 8), and 3-methoxybutyl mercaptoacetate(1T(A), Comparative Example 9) or 10 g of a compound having two thiolgroups (i.e., 2T) is used. The blue light conversion rate for each ofthe prepared quantum dot polymer composite patterns is measured, and theresults are shown in FIG. 12.

The results of FIG. 12 confirm that the compound having one thiol groupdoes not have an effect of increasing the process maintenance ratio.

While this disclosure has been described in connection with what ispresently considered to be practical exemplary embodiments, it is to beunderstood that the invention is not limited to the disclosedembodiments, but, on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims.

What is claimed is:
 1. A photosensitive composition comprising: a carboxylic acid group-containing polymer; a quantum dot; a reactive compound comprising at least two thiol groups; a photopolymerizable monomer comprising a carbon-carbon double bond; and a photoinitiator, wherein the carboxylic acid group-containing polymer comprises a copolymer of a monomer combination comprising a first monomer comprising a carboxylic acid group and a carbon-carbon double bond and a second monomer comprising a carbon-carbon double bond and a hydrophobic moiety and not comprising a carboxylic acid group.
 2. The photosensitive composition of claim 1, wherein the quantum dot comprises an organic ligand comprising a hydrophobic moiety bound to a surface thereof.
 3. The photosensitive composition of claim 2, wherein the organic ligand does not comprise a photopolymerizable functional group.
 4. The photosensitive composition of claim 2, wherein the organic ligand comprises RCOOH, RNH₂, R₂NH, R₃N, RSH, R₃PO, R₃P, ROH, RCOOR′, RPO(OH)₂, R₂POOH (wherein R and R′ are independently a C5 to C24 aliphatic hydrocarbon group or a C6 to C20 aromatic hydrocarbon group), a polymeric organic ligand, or a combination thereof.
 5. The photosensitive composition of claim 1, wherein the quantum dot comprises a Group II-VI compound, a Group III-V compound, a Group IV-VI compound, a Group IV element or compound, a Group I-III-VI compound, a Group I-II-IV-IV compound, or a combination thereof.
 6. The photosensitive composition of claim 1, wherein the carboxylic acid group-containing polymer has an acid value of greater than about 60 milligrams of KOH per gram and less than or equal to about 200 milligrams of KOH per gram.
 7. The photosensitive composition of claim 1, wherein the carboxylic acid group-containing polymer has an acid value between about 100 milligrams of KOH per gram and about 200 milligrams of KOH per gram.
 8. The photosensitive composition of claim 1, wherein the copolymer comprises a first repeating unit derived from a first monomer and a second repeating unit derived from a second monomer, wherein the first repeating unit comprises a repeating unit represented by Chemical Formula 1-1, a repeating unit represented by Chemical Formula 1-2, or a combination thereof:

wherein R¹ is hydrogen, a C1 to C3 alkyl group, or —(CH₂)_(n1)—COOH (wherein n1 is 0 to 2), R² is hydrogen, a C1 to C3 alkyl group, or —COOH, L is a single bond, a C1 to C15 aliphatic hydrocarbon group, a C6 to C30 aromatic hydrocarbon group, a C6 to C30 alicyclic hydrocarbon group, or a C1 to C15 aliphatic hydrocarbon group substituted with a C6 to C30 aromatic hydrocarbon group or a C6 to C30 alicyclic hydrocarbon group, and * indicates a portion linked to an adjacent atom;

wherein R¹ is hydrogen, a C1 to C3 alkyl group, or —(CH₂)_(n1)—COOH (wherein n1 is 0 to 2), R² is hydrogen or a C1 to C3 alkyl group, L is a C1 to C15 alkylene group, a C1 to C15 alkylene group wherein at least one methylene group is substituted with —C(═O)—, —O—, or —C(═O)O—, a C6 to C30 aromatic hydrocarbon group, a C6 to C30 alicyclic hydrocarbon group, or a C1 to C15 aliphatic hydrocarbon group substituted with a C6 to C30 aromatic hydrocarbon group or a C6 to C30 alicyclic hydrocarbon group, n is an integer of 1 to 3, and * indicates a portion linked to an adjacent atom; the second repeating unit comprises a repeating unit represented by Chemical Formula 2, a repeating unit represented by Chemical Formula 4, a repeating unit represented by Chemical Formula 5, a repeating unit represented by Chemical Formula A, or a combination thereof:

wherein R¹ is hydrogen or a C1 to C3 alkyl group, R² is a C1 to C15 aliphatic hydrocarbon group, a C6 to C30 aromatic hydrocarbon group, a C6 to C30 alicyclic hydrocarbon group, or a C1 to C15 aliphatic hydrocarbon group substituted with a C6 to C30 aromatic hydrocarbon group or a C6 to C30 alicyclic hydrocarbon group, R³ is hydrogen or a C1 to C3 alkyl group, * indicates a portion linked to an adjacent atom;

wherein R¹ is hydrogen or a C1 to C3 alkyl group, L is a C1 to C15 alkylene group, a C1 to C15 alkylene group wherein at least one methylene group is substituted with —C(═O)—, —O—, or —C(═O)O—, a C6 to C30 aromatic hydrocarbon group, a C6 to C30 alicyclic hydrocarbon group, or a C1 to C15 aliphatic hydrocarbon group substituted with a C6 to C30 aromatic hydrocarbon group or a C6 to C30 alicyclic hydrocarbon group, R² is a C1 to C15 aliphatic hydrocarbon group, a C6 to C30 aromatic hydrocarbon group, a C6 to C30 alicyclic hydrocarbon group, or a C1 to C15 aliphatic hydrocarbon group substituted with a C6 to C30 aromatic hydrocarbon group or a C6 to C30 alicyclic hydrocarbon group, R³ is hydrogen or a C1 to C3 alkyl group, n is an integer of 1 to 3, and * indicates a portion linked to an adjacent atom;

wherein each of R¹ and R² is independently hydrogen or a C1 to C3 alkyl group, Ar is a substituted or unsubstituted C6 to C30 aromatic hydrocarbon group or a substituted or unsubstituted C6 to C30 alicyclic hydrocarbon group, and * indicates a portion linked to an adjacent atom;

wherein R¹ is hydrogen or a C1 to C3 alkyl group, R² is a C1 to C15 aliphatic hydrocarbon group, a C6 to C30 aromatic hydrocarbon group, a C6 to C30 alicyclic hydrocarbon group, or a C1 to C15 aliphatic hydrocarbon group substituted with a C6 to C30 aromatic hydrocarbon group or a C6 to C30 alicyclic hydrocarbon group, R³ is hydrogen or a C1 to C3 alkyl group, and * indicates a portion linked to an adjacent atom.
 9. The photosensitive composition of claim 1, wherein the monomer combination further comprises a third monomer comprising a carbon-carbon double bond and a hydrophilic moiety and not comprising a carboxylic acid group.
 10. The photosensitive composition of claim 9, wherein the copolymer further comprises a third repeating unit derived from the third monomer, and wherein the third repeating unit is represented by Chemical Formula 3:

wherein each of R¹ and R² is independently hydrogen or a C1 to C3 alkyl group, L is a C1 to C15 alkylene group, a C1 to C15 alkylene group wherein at least one methylene group is substituted with —C(═O)—, —O—, or —C(═O)O—, a C6 to C30 aromatic hydrocarbon group, a C6 to C30 alicyclic hydrocarbon group, or a C1 to C15 aliphatic hydrocarbon group substituted with a C6 to C30 aromatic hydrocarbon group or a C6 to C30 alicyclic hydrocarbon group, Z is a hydroxyl group (—OH), a mercapto group (—SH), or an amino group (—NHR, wherein R is hydrogen or a C1 to C5 alkyl group), and * indicates a portion linked to an adjacent atom.
 11. The photosensitive composition of claim 1, wherein in the copolymer, the amount of the first repeating unit is greater than or equal to about 5 mole percent and less than or equal to about 95 mole percent.
 12. The photosensitive composition of claim 1, wherein the carboxylic acid group-containing polymer comprises a copolymer of a first monomer selected from (meth)acrylic acid and at least one second monomer and optionally third monomer selected from arylalkyl(meth)acrylate, hydroxyalkyl (meth)acrylate, and styrene.
 13. The photosensitive composition of claim 1, wherein a weight average molecular weight of the carboxylic acid group-containing polymer is greater than or equal to about 1,000 grams per mole and less than or equal to about 100,000 grams per mole.
 14. The photosensitive composition of claim 1, wherein the reactive compound comprises a compound represented by Chemical Formula 6:

wherein, in Chemical Formula 6, R¹ is hydrogen, a substituted or unsubstituted C1 to C30 linear or branched alkyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C7 to C30 arylalkyl group, a substituted or unsubstituted C3 to C30 heteroaryl group, a substituted or unsubstituted C4 to C30 heteroarylalkyl group, a substituted or unsubstituted C3 to C30 cycloalkyl group, a substituted or unsubstituted C3 to C30 heterocycloalkyl group, a C1 to C10 alkoxy group, a hydroxy group, —NH₂, a substituted or unsubstituted C1 to C30 amine group (—NRR′, wherein R and R′ are independently hydrogen or a C1 to C30 linear or branched alkyl group), an isocyanate group, a halogen, —ROR′ (wherein R is a substituted or unsubstituted C1 to C20 alkylene group and R′ is hydrogen or a C1 to C20 linear or branched alkyl group), an acyl halide (—RC(═O)X, wherein R is a substituted or unsubstituted C1 to C20 alkylene group and X is a halogen), —C(═O)OR′ (wherein R′ is hydrogen or a C1 to C20 linear or branched alkyl group), —CN, —C(═O)ONRR′ (wherein R and R′ are independently hydrogen or a C1 to C20 linear or branched alkyl group), or a combination thereof, L₁ is a carbon atom, a substituted or unsubstituted C1 to C30 alkylene group, a substituted or unsubstituted C6 to C30 cycloalkylene group, a substituted or unsubstituted C6 to C30 arylene group, or a substituted or unsubstituted C6 to C30 heteroarylene group, wherein at least one methylene (—CH₂—) of the substituted or unsubstituted C1 to C30 alkylene group is optionally replaced by sulfonyl (—S(═O)₂—), carbonyl (—C(═O)—), ether (—O—), sulfide (—S—), sulfoxide (—S(═O)—), ester (—C(═O)O—), amide (—C(═O)NR—) (wherein R is hydrogen or a C1 to C10 alkyl group), or a combination thereof, Y₁ is a single bond, a substituted or unsubstituted C1 to C30 alkylene group, a substituted or unsubstituted C2 to C30 alkenylene group, or a C1 to C30 alkylene group or a C2 to C30 alkenylene group wherein at least one methylene (—CH₂—) is replaced by sulfonyl (—S(═O)₂—), carbonyl (—C(═O)—), ether (—O—), sulfide (—S—), sulfoxide (—S(═O)—), ester (—C(═O)O—), amide (—C(═O)NR—) (wherein R is hydrogen or a C1 to C10 linear or branched alkyl group), imine (—NR—) (wherein R is hydrogen or a C1 to C10 linear or branched alkyl group), or a combination thereof, m is an integer of 1 or more, k1 is 0 or an integer of 1 or more, k2 is an integer of 1 or more, provided that the sum of m and k2 is an integer of 3 or more, provided that m does not exceed the valence of Y₁ when Y₁ is not a single bond, and provided that the sum of k1 and k2 does not exceed the valence of L₁.
 15. The photosensitive composition of claim 14, wherein the reactive compound comprises a compound represented by Chemical Formula 6-1:

wherein L₁′ is carbon, a substituted or unsubstituted C2 to C20 group derived from an alkane, a substituted or unsubstituted C6 to C30 group derived from an arene, a substituted or unsubstituted C3 to C30 group derived from a heteroarene, a substituted or unsubstituted C3 to C30 group derived from a cycloalkane, or a substituted or unsubstituted C3 to C30 group derived from a heterocycloalkane, each of Y_(a) to Y_(d) is independently a single bond, a substituted or unsubstituted C1 to C30 alkylene group, a substituted or unsubstituted C2 to C30 alkenylene group, or a C1 to C30 alkylene group or a C2 to C30 alkenylene group wherein at least one methylene (—CH₂—) is replaced by sulfonyl (—S(═O)₂—), carbonyl (—C(═O)—), ether (—O—), sulfide (—S—), sulfoxide (—S(═O)—), ester (—C(═O)O—), amide (—C(═O)NR—) (wherein R is hydrogen or a C1 to C10 linear or branched alkyl group), imine (—NR—) (wherein R is hydrogen or a C1 to C10 linear or branched alkyl group), or a combination thereof, and each of R_(a) to R_(d) is independently R¹ or SH of Chemical Formula 6, provided that at least two of R_(a) to R_(d) are SH.
 16. The photosensitive composition of claim 1, wherein the reactive compound comprises ethoxylated pentaerythritol tetra(3-mercaptopropionate), trimethylolpropane tri(2-mercaptoacetate), glycol di-3-mercaptopropionate, polypropylene glycol di(3-mercaptopropionate), ethoxylated trimethylolpropane tri(3-mercaptopropionate), glycol dimercaptoacetate, ethoxylated glycol dimercaptoacetate, 1,4-bis(3-mercaptobutyryloxy)butane, trimethylol propane tris(3-mercaptopropionate), tris[2-(3-mercaptopropionyloxy)ethyl]isocyanurate, 1,3,5-tris(3-mercaptobutyloxyethyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, pentaerythritol tetrakis(3-mercaptopropionate), pentaerythritol tetrakis(2-mercaptoacetate), 1,6-hexanedithiol, 1,3-propanedithiol, 1,2-ethanedithiol, a polyethylene glycol dithiol comprising 1 to 10 ethylene glycol repeating units, or a combination thereof.
 17. The photosensitive composition of claim 1, wherein the photopolymerizable monomer comprises alkyl(meth)acrylate, ethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol di(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, bisphenol A di(meth)acrylate, bisphenol A epoxy acrylate, trimethylolpropanetri(meth)acrylate, ethylene glycol monomethyl ether (meth)acrylate, novolac epoxy (meth)acrylate, propylene glycol di(meth)acrylate, tris(meth)acryloyloxyethyl phosphate, or a combination thereof.
 18. The photosensitive composition of claim 1, wherein a polymer composite prepared from the photosensitive composition has a blue light conversion rate of greater than or equal to about 30% of an initial value thereof after a 30 minute heat-treatment at a temperature of 180° C.
 19. The photosensitive composition of claim 1, wherein the photosensitive composition further comprises a solvent, and, based on a total amount of the composition, the photosensitive composition comprises: about 1 percent by weight to about 40 percent by weight of the quantum dots; about 0.5 percent by weight to about 35 percent by weight of the carboxylic acid group-containing polymer; about 0.5 percent by weight to about 30 percent by weight of the photopolymerizable monomer; about 0.5 percent by weight to about 40 percent by weight of the reactive compound; about 0.01 percent by weight to about 10 percent by weight of the photoinitiator; and a balance amount of the solvent.
 20. The photosensitive composition of claim 1, wherein the photosensitive composition further comprises a light diffusing agent selected from a metal oxide particle, a metal particle, and a combination thereof.
 21. A method of producing a photosensitive composition of claim 1, the method comprising: dissolving a carboxylic acid group-containing polymer in a solvent to prepare a solution; combining a plurality of quantum dots comprising an organic ligand on a surface thereof with the solution to obtain a quantum dot dispersion; and combining the quantum dot dispersion with a reactive compound comprising at least two thiol groups, a photopolymerizable monomer comprising a carbon-carbon double bond, and photoinitiator.
 22. A quantum dot-polymer composite comprising: a matrix comprising a carboxylic acid group-containing polymer and a polymerization product of a photopolymerizable monomer comprising a carbon-carbon double bond and a reactive compound comprising at least two thiol groups; and a plurality of quantum dots; wherein the carboxylic acid group-containing polymer comprises a copolymer of a monomer combination comprising a first monomer comprising a carboxylic acid group and a carbon-carbon double bond and a second monomer comprising a carbon-carbon double bond and a hydrophobic moiety and not comprising a carboxylic acid group; and the plurality of quantum dots are dispersed in the matrix.
 23. The quantum dot-polymer composite of claim 22, wherein the copolymer is a linear polymer and the photopolymerizable monomer comprises a monomer comprising at least two (meth)acrylate groups and the polymerization product comprises a crosslinked polymer.
 24. The quantum dot-polymer composite of claim 22, wherein the quantum dot comprises an organic ligand on a surface thereof and the organic ligand comprises RCOOH, RNH₂, R₂NH, R₃N, RSH, R₃PO, R₃P, ROH, RCOOR′, RPO(OH)₂, R₂POOH (wherein R and R′ are independently a C5 to C24 aliphatic hydrocarbon group or a C5 to C20 aromatic hydrocarbon group), a polymeric organic ligand, or a combination thereof.
 25. The quantum dot-polymer composite of claim 22, wherein the carboxylic acid group-containing polymer has an acid value of greater than about 60 milligrams of KOH per gram and less than or equal to about 200 milligrams of KOH per gram.
 26. The quantum dot-polymer composite of claim 22, wherein the copolymer comprises a first repeating unit derived from the first monomer and a second repeating unit derived from the second monomer, and the first repeating unit comprises a repeating unit represented by Chemical Formula 1-1, a repeating unit represented by Chemical Formula 1-2, or a combination thereof:

wherein R¹ is hydrogen, a C1 to C3 alkyl group, or —(CH₂)_(n1)—COOH (wherein n1 is 0 to 2), R² is hydrogen, a C1 to C3 alkyl group, or —COOH, L is a single bond, a C1 to C15 aliphatic hydrocarbon group, a C6 to C30 aromatic hydrocarbon group, a C6 to C30 alicyclic hydrocarbon group, or a C1 to C15 aliphatic hydrocarbon group substituted with a C6 to C30 aromatic hydrocarbon group or a C6 to C30 alicyclic hydrocarbon group, and * indicates a portion linked to an adjacent atom;

wherein R¹ is hydrogen, a C1 to C3 alkyl group, or —(CH₂)_(n1)—COOH (wherein n1 is 0 to 2), R² is hydrogen or a C1 to C3 alkyl group, L is a C1 to C15 alkylene group, a C1 to C15 alkylene group wherein at least one methylene group is substituted with —C(═O)—, —O—, or —C(═O)O—, a C6 to C30 aromatic hydrocarbon group, a C6 to C30 alicyclic hydrocarbon group, or a C1 to C15 aliphatic hydrocarbon group substituted with a C6 to C30 aromatic hydrocarbon group or a C6 to C30 alicyclic hydrocarbon group, n is an integer of 1 to 3, and * indicates a portion linked to an adjacent atom; the second repeating unit comprises a repeating unit represented by Chemical Formula 2, a repeating unit represented by Chemical Formula 4, a repeating unit represented by Chemical Formula 5, a repeating unit represented by Chemical Formula A, or a combination thereof:

wherein R¹ is hydrogen or a C1 to C3 alkyl group, R² is a C1 to C15 aliphatic hydrocarbon group, a C6 to C30 aromatic hydrocarbon group, a C6 to C30 alicyclic hydrocarbon group, or a C1 to C15 aliphatic hydrocarbon group substituted with a C6 to C30 aromatic hydrocarbon group or a C6 to C30 alicyclic hydrocarbon group, R³ is hydrogen or a C1 to C3 alkyl group, and * indicates a portion linked to an adjacent atom;

wherein R¹ is hydrogen or a C1 to C3 alkyl group, L is a C1 to C15 alkylene group, a C1 to C15 alkylene group wherein at least one methylene group is substituted with —C(═O)—, —O—, or —C(═O)O—, a C6 to C30 aromatic hydrocarbon group, a C6 to C30 alicyclic hydrocarbon group, or a C1 to C15 aliphatic hydrocarbon group substituted with a C6 to C30 aromatic hydrocarbon group or a C6 to C30 alicyclic hydrocarbon group, R² is a C1 to C15 aliphatic hydrocarbon group, a C6 to C30 aromatic hydrocarbon group, a C6 to C30 alicyclic hydrocarbon group, or a C1 to C15 aliphatic hydrocarbon group substituted with a C6 to C30 aromatic hydrocarbon group or a C6 to C30 alicyclic hydrocarbon group, R³ is hydrogen or a C1 to C3 alkyl group, n is an integer of 1 to 3, and * indicates a portion linked to an adjacent atom;

wherein each of R¹ and R² is independently hydrogen or a C1 to C3 alkyl group, Ar is a substituted or unsubstituted C6 to C30 aromatic hydrocarbon group or a substituted or unsubstituted C6 to C30 alicyclic hydrocarbon group, and * indicates a portion linked to an adjacent atom;

wherein R¹ is hydrogen or a C1 to C3 alkyl group, R² is a C1 to C15 aliphatic hydrocarbon group, a C6 to C30 aromatic hydrocarbon group, a C6 to C30 alicyclic hydrocarbon group, or a C1 to C15 aliphatic hydrocarbon group substituted with a C6 to C30 aromatic hydrocarbon group or a C6 to C30 alicyclic hydrocarbon group, R³ is hydrogen or a C1 to C3 alkyl group, and * indicates a portion linked to an adjacent atom.
 27. The quantum dot-polymer composite of claim 22, wherein the monomer combination further comprises a third monomer comprising a carbon-carbon double bond and a hydrophilic moiety and not comprising a carboxylic acid group.
 28. The quantum dot-polymer composite of claim 22, wherein the copolymer further comprises a third repeating unit derived from the third monomer, and the third repeating unit is represented by Chemical Formula 3:

wherein each of R¹ and R² is independently hydrogen or a C1 to C3 alkyl group, L is a C1 to C15 alkylene group, a C1 to C15 alkylene group wherein at least one methylene group is substituted with —C(═O)—, —O—, or —C(═O)O—, a C6 to C30 aromatic hydrocarbon group, a C6 to C30 alicyclic hydrocarbon group, or a C1 to C15 aliphatic hydrocarbon group substituted with a C6 to C30 aromatic hydrocarbon group or a C6 to C30 alicyclic hydrocarbon group, Z is a hydroxyl group (—OH), a mercapto group (—SH), or an amino group (—NHR, wherein R is hydrogen or a C1 to C5 alkyl group), and * indicates a portion linked to an adjacent atom.
 29. The quantum dot-polymer composite of claim 22, wherein in the copolymer, the amount of the first repeating unit is greater than or equal to about 5 mole percent and less than or equal to about 95 mole percent.
 30. The quantum dot-polymer composite of claim 22, wherein the reactive compound comprises a compound represented by Chemical Formula 6:

wherein, in Chemical Formula 6, R¹ is hydrogen, a substituted or unsubstituted C1 to C30 linear or branched alkyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C7 to C30 arylalkyl group, a substituted or unsubstituted C3 to C30 heteroaryl group, a substituted or unsubstituted C4 to C30 heteroarylalkyl group, a substituted or unsubstituted C3 to C30 cycloalkyl group, a substituted or unsubstituted C3 to C30 heterocycloalkyl group, a C1 to C10 alkoxy group, a hydroxy group, —NH₂, a substituted or unsubstituted C1 to C30 amine group (—NRR′, wherein R and R′ are independently hydrogen or a C1 to C30 linear or branched alkyl group), an isocyanate group, a halogen, —ROR′ (wherein R is a substituted or unsubstituted C1 to C20 alkylene group and R′ is hydrogen or a C1 to C20 linear or branched alkyl group), an acyl halide (—RC(═O)X, wherein R is a substituted or unsubstituted C1 to C20 alkylene group and X is a halogen), —C(═O)OR′ (wherein R′ is hydrogen or a C1 to C20 linear or branched alkyl group), —CN, —C(═O)ONRR′ (wherein R and R′ are independently hydrogen or a C1 to C20 linear or branched alkyl group), or a combination thereof, L₁ is a carbon atom, a substituted or unsubstituted C1 to C30 alkylene group, a substituted or unsubstituted C6 to C30 cycloalkylene group, a substituted or unsubstituted C6 to C30 arylene group, or a substituted or unsubstituted C6 to C30 heteroarylene group, wherein at least one methylene (—CH₂—) of the substituted or unsubstituted C1 to C30 alkylene group is optionally replaced by sulfonyl (—S(═O)₂—), carbonyl (—C(═O)—), ether (—O—), sulfide (—S—), sulfoxide (—S(═O)—), ester (—C(═O)O—), amide (—C(═O)NR—) (wherein R is hydrogen or a C1 to C10 alkyl group), or a combination thereof, Y₁ is a single bond, a substituted or unsubstituted C1 to C30 alkylene group, a substituted or unsubstituted C2 to C30 alkenylene group, or a C1 to C30 alkylene group or a C2 to C30 alkenylene group wherein at least one methylene (—CH₂—) is replaced by sulfonyl (—S(═O)₂—), carbonyl (—C(═O)—), ether (—O—), sulfide (—S—), sulfoxide (—S(═O)—), ester (—C(═O)O—), amide (—C(═O)NR—) (wherein R is hydrogen or a C1 to C10 linear or branched alkyl group), imine (—NR—) (wherein R is hydrogen or a C1 to C10 linear or branched alkyl group), or a combination thereof, m is an integer of 1 or more, k1 is 0 or an integer of 1 or more, k2 is an integer of 1 or more, provided that the sum of m and k2 is an integer of 3 or more, provided that m does not exceed the valence of Y₁ when Y₁ is not a single bond, and provided that the sum of k1 and k2 does not exceed the valence of L₁.
 31. The quantum dot-polymer composite pattern of claim 22, wherein the reactive compound comprises a compound represented by Chemical Formula 6-1:

wherein L₁′ is carbon, a substituted or unsubstituted tetravalent C2 to C20 group derived from an alkane, a substituted or unsubstituted C6 to C30 group derived from an arene, a substituted or unsubstituted C3 to C30 group derived from a heteroarene, a substituted or unsubstituted C3 to C30 group derived from a cycloalkane, or a substituted or unsubstituted C3 to C30 group derived from a heterocycloalkane, each of Y_(a) to Y_(d) is independently a single bond, a substituted or unsubstituted C1 to C30 alkylene group, a substituted or unsubstituted C2 to C30 alkenylene group, or a C1 to C30 alkylene group or a C2 to C30 alkenylene group wherein at least one methylene (—CH₂—) is replaced by sulfonyl (—S(═O)₂—), carbonyl (—C(═O)—), ether (—O—), sulfide (—S—), sulfoxide (—S(═O)—), ester (—C(═O)O—), amide (—C(═O)NR—) (wherein R is hydrogen or a C1 to C10 linear or branched alkyl group), imine (—NR—) (wherein R is hydrogen or a C1 to C10 linear or branched alkyl group), or a combination thereof, and each of R_(a) to R_(d) is independently R¹ or SH of Chemical Formula 6, provided that at least two of R_(a) to R_(d) are SH.
 32. A color filter comprising a quantum dot-polymer composite of claim
 22. 33. A display device comprising a quantum dot-polymer composite of claim
 22. 